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【323799】2024八年级数学上册 第十五章 二次根式综合素质评价(新版)冀教版

时间:2025-01-15 20:46:45 作者: 字数:8201字
简介:


第十五章综合素质评价

 

 

 





一、选择题(每题3分,共36)

1在式子 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a> (x0) <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a> (y=-2) <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a> (x0) <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a> xy中,二次根式有(  )

A.2 B.3 C.4 D.5

2[2024·邢台期末] <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a> =-a1,则a的值可以是(  )

A.4 B.2 C.0 D.2

3下列计算正确的是(  )

A.326 B. <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a> =- <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a>

C.(2a2)22a4 D. <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a> 2 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a> 3 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a>

4[母题·教材P106复习题CT1]  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a> 是整数,则正整数n的最小值是(  )

A.2 B.3 C.4 D.5

5已知a <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a> 1b <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a> ,则ab的关系为(  )

A. ab B. ab1 C. a=-b D. ab=-1

6已知abc为△ABC的三边长,且 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a> +|bc|=0,则abc的大小关系是(  )

A. abc B. abc C. abc D. abc

7已知ab2 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a> 1ab <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a> ,则(a1)(b1)的值为(  )

A. <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a> B.3 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a> C.3 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a> 2 D. <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a> 1

8实数ab在数轴上的对应点的位置如图所示,那么化简

ab|- <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a> 的结果是(  )

 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a>

(8)

A.2ab B. b C.2ab D.b

9[母题·教材P106复习题BT3] x <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a> 1时,代数式x22x3的值是(  )

A.4 B.5 C.6 D.7

10如图,长方形内有两个相邻的正方形,其面积分别为28,则图中阴影部分的面积为(  )

 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a>

(10)

A. <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a> B.2 C.2 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a> D.6

11如果x6 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a> 的小数部分,那么x2的值为(  )

A.64 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a> B.16 C.32 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a> D.64 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a>

12[新考法·新定义运算]对于任意的正数mn,定义运算“※”:mn <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a> 计算(3※2)×(8※12)的结果为(  )

A.24 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a> B.2 C.2 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a> D.20

二、填空题(每题3分,共12)

13[2024·邢台第三中学月考] <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a> 有意义,则n的取值范围是    ;若 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a> 是整数,则整数n的值是    .

14[母题·教材P81复习题AT6] 比较大小:3 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a>     2 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a> (填“>”“<”或“=”).

15计算: <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a> 3 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a>     .

16[2022·宜宾]《数书九章》是中国南宋时期杰出数学家秦九韶的著作,书中提出了已知三角形三边abc求面积的公式,其求法是:“以小斜幂并大斜幂减中斜幂,余半之,自乘于上,以小斜幂乘大斜幂减上,余四约之,为实.一为从隅,开平方得积.”若把以上这段文字写成公式,即为S <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a> .现有周长为18的三角形的三边满足abc4∶3∶2,则用以上给出的公式求得这个三角形的面积为    .

三、解答题(1722题每题10分,第2312分,共72)

17[母题·教材P1011] 计算:

(1) <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a> × <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a> (2)( <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a> ÷3 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a> .



18(1)先化简,再求值: <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a> ÷ <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a> ,其中a2 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a> b2 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a> .

(2)已知ab=-2ab <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a> ,求 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a> 的值.



19已知abc是△ABC的三边长,化简 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a> .






20[2024·石家庄第五十四中学期末]老师设计了接力游戏,用合作的方式完成二次根式的运算.规则:每人只能看到前一人给的式子,并进行一步计算,再将结果传递给下一人,最后完成化简.过程如图所示:

 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a>

(1)接力中,自己负责的一步出现错误的是    

(2)请给出正确的求解过程.









21拦河坝的横断面是梯形,如图,其上底是 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a> m,下底是

 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a> m,高是 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a> m.

 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a>

(1)求横断面的面积.

(2)若用300m3的土,可修多长的拦河坝.









22观察下列各式:

 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a> 1 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a> 1 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a>

 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a> 1 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a> 1 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a>

 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a> 1 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a> 1 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a> .

请你根据上面三个等式提供的信息,猜想:

(1) <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a>     

(2)请你按照上面每个等式反映的规律,写出用n(n为正整数)表示的

等式:    

(3)利用上述规律计算: <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a> (仿照上式写出过程).







23[新考法·阅读类比法]  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a> · <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a> a(a≥0)

( <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a> 1)( <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a> 1)b1(b≥0),两个含有二次根式的代数式相乘,积不含二次根式,我们称这两个代数式互为有理化因式.例如( <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a> 1)( <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a> 1)( <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a> )211( <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a> )( <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a> )( <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a> )2( <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a> )22,其中 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a> 1 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a> 1 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a> 都是互为有理化因式.在进行二次根式计算时,利用有理化因式,可以将分母有理化.请完成下列问题:

(1)计算: <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a>      <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a>     

(2)已知有理数ab满足 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a> 2 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a> 1,则a    

b    

(3)计算: <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a> +…+ <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a> .






答案

一、1. B【点拨】 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a> x0), <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a> 是二次根式; <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a>

y=-2), <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a> x0)没有意义, <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a> 不是二次根式,xy是整式,即二次根式有3.

2. D【点拨】∵ <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a> =-a1=-(a1),

a1≤0,则a1.

故选项D符合题意,选项ABC不符合题意.

3. D

4. B【点拨】 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a> 5 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a> ,要使 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a> 为整数,那么3n必须为完全平方数,则正整数n的最小值为3.

5. A 【点拨】b <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a> 1a.

6. B【点拨】原等式可化为|ab|+|bc|=0

ab0bc0,∴abc.

7. A【点拨】(a1)(b1)=ab-(ab)-1.ab2 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a> 1ab <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a> 整体代入上式,得原式= <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a> -(2 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a> 1)-1=- <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a> .

8. B【点拨】由数轴上点的位置知a0ab0,所以|ab|- <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a> baab.

9. D【点拨】x22x3=(x122=( <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a> 1122527.

10. B【点拨】设长方形的长和宽分别为abab0),则大正方形的边长为b,小正方形的边长为ab.由题可得,b28,(ab22,解得b2 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a> ab <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a> ,即可求得左边的小长方形的面积为bab)=2 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a> × <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a> 4,所以图中阴影部分的面积为422.

11. A【点拨】∵124,∴1 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a> 2.∴2<- <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a> <-1.∴46 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a> 5.∴6 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a> 的小数部分x6 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a> 42 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a> .∴x2=(2 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a> 244 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a> 264 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a> .

12. B【点拨】∵32,∴3※2 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a> .∵812,∴8※12 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a> .∴3※2×8※12)=( <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a> ×2× <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a> )=2.

二、13. n1134【点拨】∵ <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a> 有意义,

n10,解得n1.

 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a> 是整数,n是整数,

n112n13

解得n13n4.

14. 15. <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a>

16.3 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a> 【点拨】∵周长为18的三角形的三边满足a∶b∶c432,∴设a4k,则b3kc2k.∴4k3k2k18,解得k2.∴a8b6c4.

S <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a>

 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a>

 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a> 3 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a> .

三、17.【解】(1)原式= <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a> × <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a> × <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a>

19

10.

2)原式=(3 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a> 2 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a> ÷3 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a>

1 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a> .

18.1)【解】原式= <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a> ÷ <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a> · <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a> ,当a2 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a> b2 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a> 时,原式= <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a> .

2)由题意知a0b0,所以原式= <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a>

 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a> =- <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a> 2 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a> .

19.【解】∵abc是△ABC的三边长,

abc0bca0cba0

原式=abc-(bca)-(cba)=3abc.

20.【解】(1)甲、乙、丁【点拨】 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a> -( <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a> )-2 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a> ,故甲错误;

 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a> ,故乙错误;

 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a> 3 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a> ,故丙正确;

 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a> 3 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a> 已是最简,不能再合并了,故丁错误.

自己负责的一步出现错误的是甲、乙、丁.

2 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a> -( <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a> )-2 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a> 2 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a> .

21.【解】(1 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a> × <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a> × <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a> ×2 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a> 4 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a> × <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a> ×6 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a> × <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a> 3 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a> m2.

答:横断面的面积为3 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a> m2.

2 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a> m.

答:可修 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a> m长的拦河坝.

22.【解】(11 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a> 1 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a>

2 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a> 1 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a> 1 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a>

3 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a> 1 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a> 1 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a> .

23.【解】(1 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a> 【点拨】 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a>

 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a> .

2)-1;-1【点拨】∵ <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a> 2 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a> 1

 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a> 2 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a> 1.

 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a> 2 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a> 1.

 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a> 2 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a> 1.

a2 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a> )-b <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a> 1)=2 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a> 1.

2a <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a> a <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a> bb2 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a> 1.

2ab)- <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a> ab)=2 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a> 1.

ab都是有理数,

 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a>

3)∵ <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a>

 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a>

 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a>

 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a> +…+ <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a>

 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a>  <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a> +…+ <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a>

 <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/279/" title="综合" class="c1" target="_blank">综合</a> <a href="/tags/300/" title="素质" class="c1" target="_blank">素质</a> <a href="/tags/499/" title="评价" class="c1" target="_blank">评价</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a> .