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【331446】2019-2020学年七年级第二学期期末数学测试卷(地区未知)

时间:2025-02-05 18:17:15 作者: 字数:6189字
简介:

七年级第二学期期末数学测试卷


注意事项:本卷共大题,计23小题,满分150分,考试时间120分钟


一、选择题(本题满分40分,每小题4分。将唯一正确答案前的代号填入下面答题栏内)

题号

1

2

3

4

5

6

7

8

9

10

答案











19的平方根为( )

A3 B、-3 C±3 D <a href="/tags/4/" title="测试" class="c1" target="_blank">测试</a> <a href="/tags/54/" title="试卷" class="c1" target="_blank">试卷</a> <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/208/" title="学期" class="c1" target="_blank">学期</a> <a href="/tags/255/" title="学年" class="c1" target="_blank">学年</a> <a href="/tags/978/" title="地区" class="c1" target="_blank">地区</a>

2、下列四个实数中,是无理数的是( )

  A <a href="/tags/4/" title="测试" class="c1" target="_blank">测试</a> <a href="/tags/54/" title="试卷" class="c1" target="_blank">试卷</a> <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/208/" title="学期" class="c1" target="_blank">学期</a> <a href="/tags/255/" title="学年" class="c1" target="_blank">学年</a> <a href="/tags/978/" title="地区" class="c1" target="_blank">地区</a> B <a href="/tags/4/" title="测试" class="c1" target="_blank">测试</a> <a href="/tags/54/" title="试卷" class="c1" target="_blank">试卷</a> <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/208/" title="学期" class="c1" target="_blank">学期</a> <a href="/tags/255/" title="学年" class="c1" target="_blank">学年</a> <a href="/tags/978/" title="地区" class="c1" target="_blank">地区</a> C <a href="/tags/4/" title="测试" class="c1" target="_blank">测试</a> <a href="/tags/54/" title="试卷" class="c1" target="_blank">试卷</a> <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/208/" title="学期" class="c1" target="_blank">学期</a> <a href="/tags/255/" title="学年" class="c1" target="_blank">学年</a> <a href="/tags/978/" title="地区" class="c1" target="_blank">地区</a> D <a href="/tags/4/" title="测试" class="c1" target="_blank">测试</a> <a href="/tags/54/" title="试卷" class="c1" target="_blank">试卷</a> <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/208/" title="学期" class="c1" target="_blank">学期</a> <a href="/tags/255/" title="学年" class="c1" target="_blank">学年</a> <a href="/tags/978/" title="地区" class="c1" target="_blank">地区</a>

3、下列计算正确的是( )

A <a href="/tags/4/" title="测试" class="c1" target="_blank">测试</a> <a href="/tags/54/" title="试卷" class="c1" target="_blank">试卷</a> <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/208/" title="学期" class="c1" target="_blank">学期</a> <a href="/tags/255/" title="学年" class="c1" target="_blank">学年</a> <a href="/tags/978/" title="地区" class="c1" target="_blank">地区</a> B <a href="/tags/4/" title="测试" class="c1" target="_blank">测试</a> <a href="/tags/54/" title="试卷" class="c1" target="_blank">试卷</a> <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/208/" title="学期" class="c1" target="_blank">学期</a> <a href="/tags/255/" title="学年" class="c1" target="_blank">学年</a> <a href="/tags/978/" title="地区" class="c1" target="_blank">地区</a> C <a href="/tags/4/" title="测试" class="c1" target="_blank">测试</a> <a href="/tags/54/" title="试卷" class="c1" target="_blank">试卷</a> <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/208/" title="学期" class="c1" target="_blank">学期</a> <a href="/tags/255/" title="学年" class="c1" target="_blank">学年</a> <a href="/tags/978/" title="地区" class="c1" target="_blank">地区</a> D <a href="/tags/4/" title="测试" class="c1" target="_blank">测试</a> <a href="/tags/54/" title="试卷" class="c1" target="_blank">试卷</a> <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/208/" title="学期" class="c1" target="_blank">学期</a> <a href="/tags/255/" title="学年" class="c1" target="_blank">学年</a> <a href="/tags/978/" title="地区" class="c1" target="_blank">地区</a>

4、下列分解因式错误的是( )

A <a href="/tags/4/" title="测试" class="c1" target="_blank">测试</a> <a href="/tags/54/" title="试卷" class="c1" target="_blank">试卷</a> <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/208/" title="学期" class="c1" target="_blank">学期</a> <a href="/tags/255/" title="学年" class="c1" target="_blank">学年</a> <a href="/tags/978/" title="地区" class="c1" target="_blank">地区</a> B <a href="/tags/4/" title="测试" class="c1" target="_blank">测试</a> <a href="/tags/54/" title="试卷" class="c1" target="_blank">试卷</a> <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/208/" title="学期" class="c1" target="_blank">学期</a> <a href="/tags/255/" title="学年" class="c1" target="_blank">学年</a> <a href="/tags/978/" title="地区" class="c1" target="_blank">地区</a>

C <a href="/tags/4/" title="测试" class="c1" target="_blank">测试</a> <a href="/tags/54/" title="试卷" class="c1" target="_blank">试卷</a> <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/208/" title="学期" class="c1" target="_blank">学期</a> <a href="/tags/255/" title="学年" class="c1" target="_blank">学年</a> <a href="/tags/978/" title="地区" class="c1" target="_blank">地区</a> D <a href="/tags/4/" title="测试" class="c1" target="_blank">测试</a> <a href="/tags/54/" title="试卷" class="c1" target="_blank">试卷</a> <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/208/" title="学期" class="c1" target="_blank">学期</a> <a href="/tags/255/" title="学年" class="c1" target="_blank">学年</a> <a href="/tags/978/" title="地区" class="c1" target="_blank">地区</a>

5、已知 <a href="/tags/4/" title="测试" class="c1" target="_blank">测试</a> <a href="/tags/54/" title="试卷" class="c1" target="_blank">试卷</a> <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/208/" title="学期" class="c1" target="_blank">学期</a> <a href="/tags/255/" title="学年" class="c1" target="_blank">学年</a> <a href="/tags/978/" title="地区" class="c1" target="_blank">地区</a>  <a href="/tags/4/" title="测试" class="c1" target="_blank">测试</a> <a href="/tags/54/" title="试卷" class="c1" target="_blank">试卷</a> <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/208/" title="学期" class="c1" target="_blank">学期</a> <a href="/tags/255/" title="学年" class="c1" target="_blank">学年</a> <a href="/tags/978/" title="地区" class="c1" target="_blank">地区</a> ,则 <a href="/tags/4/" title="测试" class="c1" target="_blank">测试</a> <a href="/tags/54/" title="试卷" class="c1" target="_blank">试卷</a> <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/208/" title="学期" class="c1" target="_blank">学期</a> <a href="/tags/255/" title="学年" class="c1" target="_blank">学年</a> <a href="/tags/978/" title="地区" class="c1" target="_blank">地区</a> 的值为( )

A7 B5 C3 D1

6、已知ambm,则下面结论中正确的是( )

Aab Bab C  <a href="/tags/4/" title="测试" class="c1" target="_blank">测试</a> <a href="/tags/54/" title="试卷" class="c1" target="_blank">试卷</a> <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/208/" title="学期" class="c1" target="_blank">学期</a> <a href="/tags/255/" title="学年" class="c1" target="_blank">学年</a> <a href="/tags/978/" title="地区" class="c1" target="_blank">地区</a> D  <a href="/tags/4/" title="测试" class="c1" target="_blank">测试</a> <a href="/tags/54/" title="试卷" class="c1" target="_blank">试卷</a> <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/208/" title="学期" class="c1" target="_blank">学期</a> <a href="/tags/255/" title="学年" class="c1" target="_blank">学年</a> <a href="/tags/978/" title="地区" class="c1" target="_blank">地区</a>  <a href="/tags/4/" title="测试" class="c1" target="_blank">测试</a> <a href="/tags/54/" title="试卷" class="c1" target="_blank">试卷</a> <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/208/" title="学期" class="c1" target="_blank">学期</a> <a href="/tags/255/" title="学年" class="c1" target="_blank">学年</a> <a href="/tags/978/" title="地区" class="c1" target="_blank">地区</a>

7 <a href="/tags/4/" title="测试" class="c1" target="_blank">测试</a> <a href="/tags/54/" title="试卷" class="c1" target="_blank">试卷</a> <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/208/" title="学期" class="c1" target="_blank">学期</a> <a href="/tags/255/" title="学年" class="c1" target="_blank">学年</a> <a href="/tags/978/" title="地区" class="c1" target="_blank">地区</a> 不等式 <a href="/tags/4/" title="测试" class="c1" target="_blank">测试</a> <a href="/tags/54/" title="试卷" class="c1" target="_blank">试卷</a> <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/208/" title="学期" class="c1" target="_blank">学期</a> <a href="/tags/255/" title="学年" class="c1" target="_blank">学年</a> <a href="/tags/978/" title="地区" class="c1" target="_blank">地区</a> 的解集在数轴上表示正确的是( )


 <a href="/tags/4/" title="测试" class="c1" target="_blank">测试</a> <a href="/tags/54/" title="试卷" class="c1" target="_blank">试卷</a> <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/208/" title="学期" class="c1" target="_blank">学期</a> <a href="/tags/255/" title="学年" class="c1" target="_blank">学年</a> <a href="/tags/978/" title="地区" class="c1" target="_blank">地区</a>

8、如图,直线ABCDEF两两相交,则图中为同旁内角的角共有(  )对。

A <a href="/tags/4/" title="测试" class="c1" target="_blank">测试</a> <a href="/tags/54/" title="试卷" class="c1" target="_blank">试卷</a> <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/208/" title="学期" class="c1" target="_blank">学期</a> <a href="/tags/255/" title="学年" class="c1" target="_blank">学年</a> <a href="/tags/978/" title="地区" class="c1" target="_blank">地区</a> 3 B4 C5 D6

 <a href="/tags/4/" title="测试" class="c1" target="_blank">测试</a> <a href="/tags/54/" title="试卷" class="c1" target="_blank">试卷</a> <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/208/" title="学期" class="c1" target="_blank">学期</a> <a href="/tags/255/" title="学年" class="c1" target="_blank">学年</a> <a href="/tags/978/" title="地区" class="c1" target="_blank">地区</a>




9、如图所示,共有3个方格块,现在要把上面的方格块与下面的两个方格块合成一

个长方形的整体,则应将上面的方格块(  )

A、向右平移1格,向下3 B、向右平移1格,向下4

C、向右平移2格,向下4 D、向右平移2格,向下3

10、把一张长方形的纸片按如图所示的方式折叠,EMFM为折痕,折叠后的C点落在B′MB′M的延长线上,那么∠EMF的度数是( )

A85° B90° C95° D100°


二、填空题(本大题共4小题,每小题5分,满分20分)

11、氢原子中电子和原子核之间最近距离为0.000 000 003 05厘米,

 <a href="/tags/4/" title="测试" class="c1" target="_blank">测试</a> <a href="/tags/54/" title="试卷" class="c1" target="_blank">试卷</a> <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/208/" title="学期" class="c1" target="_blank">学期</a> <a href="/tags/255/" title="学年" class="c1" target="_blank">学年</a> <a href="/tags/978/" title="地区" class="c1" target="_blank">地区</a> 科学记数法表示为________________________厘米.

12、当x 时,分式 <a href="/tags/4/" title="测试" class="c1" target="_blank">测试</a> <a href="/tags/54/" title="试卷" class="c1" target="_blank">试卷</a> <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/208/" title="学期" class="c1" target="_blank">学期</a> <a href="/tags/255/" title="学年" class="c1" target="_blank">学年</a> <a href="/tags/978/" title="地区" class="c1" target="_blank">地区</a> 没有意义。

13、一个宽度相等的纸条,如下图这样折叠,则∠1等于

14如果y= <a href="/tags/4/" title="测试" class="c1" target="_blank">测试</a> <a href="/tags/54/" title="试卷" class="c1" target="_blank">试卷</a> <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/208/" title="学期" class="c1" target="_blank">学期</a> <a href="/tags/255/" title="学年" class="c1" target="_blank">学年</a> <a href="/tags/978/" title="地区" class="c1" target="_blank">地区</a> ,那么用y的代数式表示x

三、计算 <a href="/tags/4/" title="测试" class="c1" target="_blank">测试</a> <a href="/tags/54/" title="试卷" class="c1" target="_blank">试卷</a> <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/208/" title="学期" class="c1" target="_blank">学期</a> <a href="/tags/255/" title="学年" class="c1" target="_blank">学年</a> <a href="/tags/978/" title="地区" class="c1" target="_blank">地区</a> (本大题共2小题,每小题6分,满分12分)

15、(1)、(2)2( <a href="/tags/4/" title="测试" class="c1" target="_blank">测试</a> <a href="/tags/54/" title="试卷" class="c1" target="_blank">试卷</a> <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/208/" title="学期" class="c1" target="_blank">学期</a> <a href="/tags/255/" title="学年" class="c1" target="_blank">学年</a> <a href="/tags/978/" title="地区" class="c1" target="_blank">地区</a> )-1+ <a href="/tags/4/" title="测试" class="c1" target="_blank">测试</a> <a href="/tags/54/" title="试卷" class="c1" target="_blank">试卷</a> <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/208/" title="学期" class="c1" target="_blank">学期</a> <a href="/tags/255/" title="学年" class="c1" target="_blank">学年</a> <a href="/tags/978/" title="地区" class="c1" target="_blank">地区</a> -( <a href="/tags/4/" title="测试" class="c1" target="_blank">测试</a> <a href="/tags/54/" title="试卷" class="c1" target="_blank">试卷</a> <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/208/" title="学期" class="c1" target="_blank">学期</a> <a href="/tags/255/" title="学年" class="c1" target="_blank">学年</a> <a href="/tags/978/" title="地区" class="c1" target="_blank">地区</a> ) (2)、(2x)2(6x312x4) ÷2x2








四、(本大题共4小题,每小题8分,满分32分)

16解不等式组 <a href="/tags/4/" title="测试" class="c1" target="_blank">测试</a> <a href="/tags/54/" title="试卷" class="c1" target="_blank">试卷</a> <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/208/" title="学期" class="c1" target="_blank">学期</a> <a href="/tags/255/" title="学年" class="c1" target="_blank">学年</a> <a href="/tags/978/" title="地区" class="c1" target="_blank">地区</a> 17、解方程: <a href="/tags/4/" title="测试" class="c1" target="_blank">测试</a> <a href="/tags/54/" title="试卷" class="c1" target="_blank">试卷</a> <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/208/" title="学期" class="c1" target="_blank">学期</a> <a href="/tags/255/" title="学年" class="c1" target="_blank">学年</a> <a href="/tags/978/" title="地区" class="c1" target="_blank">地区</a>

【解】 【解】









18、分解因式:a2(x-y)2+2a(x-y)3+(x-y)4







19、先化简,再求值: <a href="/tags/4/" title="测试" class="c1" target="_blank">测试</a> <a href="/tags/54/" title="试卷" class="c1" target="_blank">试卷</a> <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/208/" title="学期" class="c1" target="_blank">学期</a> <a href="/tags/255/" title="学年" class="c1" target="_blank">学年</a> <a href="/tags/978/" title="地区" class="c1" target="_blank">地区</a> ,其中 <a href="/tags/4/" title="测试" class="c1" target="_blank">测试</a> <a href="/tags/54/" title="试卷" class="c1" target="_blank">试卷</a> <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/208/" title="学期" class="c1" target="_blank">学期</a> <a href="/tags/255/" title="学年" class="c1" target="_blank">学年</a> <a href="/tags/978/" title="地区" class="c1" target="_blank">地区</a>

【解】











五、(本大题共2小题,每小题10分,满分20分)

20、观察下列等式: <a href="/tags/4/" title="测试" class="c1" target="_blank">测试</a> <a href="/tags/54/" title="试卷" class="c1" target="_blank">试卷</a> <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/208/" title="学期" class="c1" target="_blank">学期</a> <a href="/tags/255/" title="学年" class="c1" target="_blank">学年</a> <a href="/tags/978/" title="地区" class="c1" target="_blank">地区</a>  <a href="/tags/4/" title="测试" class="c1" target="_blank">测试</a> <a href="/tags/54/" title="试卷" class="c1" target="_blank">试卷</a> <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/208/" title="学期" class="c1" target="_blank">学期</a> <a href="/tags/255/" title="学年" class="c1" target="_blank">学年</a> <a href="/tags/978/" title="地区" class="c1" target="_blank">地区</a>  <a href="/tags/4/" title="测试" class="c1" target="_blank">测试</a> <a href="/tags/54/" title="试卷" class="c1" target="_blank">试卷</a> <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/208/" title="学期" class="c1" target="_blank">学期</a> <a href="/tags/255/" title="学年" class="c1" target="_blank">学年</a> <a href="/tags/978/" title="地区" class="c1" target="_blank">地区</a> ,……

1)探索这些等式中的规律,直接写出第n个等式(用含n的等式表示)。

2)试说明你的结论的正确性。

【解】











2DrawObject1 1、如图7,直线AB∥CD,直线EF分别交直线ABCD于点EFFH平分∠EFD,若

FEH=110º,求∠EHF的度数。

【解】








六、(本题满分12分)

22、已知,AC⊥ABEF⊥BCAD⊥BC,∠1=∠2,请问AC⊥DG吗?请写出推理过程。

 <a href="/tags/4/" title="测试" class="c1" target="_blank">测试</a> <a href="/tags/54/" title="试卷" class="c1" target="_blank">试卷</a> <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/208/" title="学期" class="c1" target="_blank">学期</a> <a href="/tags/255/" title="学年" class="c1" target="_blank">学年</a> <a href="/tags/978/" title="地区" class="c1" target="_blank">地区</a>

【解】










七、(本题满分14分)

23、北京奥运会开幕前,某体育用品商场预测某品牌运动服能够畅销,就用32000元购进了一批这种运动服,上市后很快脱销,商场又用68000元购进第二批这种运动服,所购数量是第一批购进数量的2倍,但每套进价多了10元。

1)该商场两次共购进这种运动服多少套?

2)如果这两批运动服每套的售价相同,且全部售完后总利润率不低于20%,那么每套售价至少是多少元?(利润率 <a href="/tags/4/" title="测试" class="c1" target="_blank">测试</a> <a href="/tags/54/" title="试卷" class="c1" target="_blank">试卷</a> <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/208/" title="学期" class="c1" target="_blank">学期</a> <a href="/tags/255/" title="学年" class="c1" target="_blank">学年</a> <a href="/tags/978/" title="地区" class="c1" target="_blank">地区</a>

【解】










七年级第二学期数学测试卷参考答案

一、选择题:

1C 2B 3D 4A 5C 6C 7B 8D 9C 10B


二、填空题:

113.05 ×10-9 12=3 1360° 14x= <a href="/tags/4/" title="测试" class="c1" target="_blank">测试</a> <a href="/tags/54/" title="试卷" class="c1" target="_blank">试卷</a> <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/208/" title="学期" class="c1" target="_blank">学期</a> <a href="/tags/255/" title="学年" class="c1" target="_blank">学年</a> <a href="/tags/978/" title="地区" class="c1" target="_blank">地区</a>

三、

15、(1=4-(-2+-2)-4 ……4′

= 4+224 ……5′

= 0 ……6′

2= 4x2(36x2) ……3′

= 4x236x2 ……4′

=10x23 ……6′


四、

16解:由(1)得: <a href="/tags/4/" title="测试" class="c1" target="_blank">测试</a> <a href="/tags/54/" title="试卷" class="c1" target="_blank">试卷</a> <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/208/" title="学期" class="c1" target="_blank">学期</a> <a href="/tags/255/" title="学年" class="c1" target="_blank">学年</a> <a href="/tags/978/" title="地区" class="c1" target="_blank">地区</a> ……3′

 <a href="/tags/4/" title="测试" class="c1" target="_blank">测试</a> <a href="/tags/54/" title="试卷" class="c1" target="_blank">试卷</a> <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/208/" title="学期" class="c1" target="_blank">学期</a> <a href="/tags/255/" title="学年" class="c1" target="_blank">学年</a> <a href="/tags/978/" title="地区" class="c1" target="_blank">地区</a>2)得: <a href="/tags/4/" title="测试" class="c1" target="_blank">测试</a> <a href="/tags/54/" title="试卷" class="c1" target="_blank">试卷</a> <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/208/" title="学期" class="c1" target="_blank">学期</a> <a href="/tags/255/" title="学年" class="c1" target="_blank">学年</a> <a href="/tags/978/" title="地区" class="c1" target="_blank">地区</a> ……6′

在数轴上表示出不等式组的解集为



不等式组的解集为 <a href="/tags/4/" title="测试" class="c1" target="_blank">测试</a> <a href="/tags/54/" title="试卷" class="c1" target="_blank">试卷</a> <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/208/" title="学期" class="c1" target="_blank">学期</a> <a href="/tags/255/" title="学年" class="c1" target="_blank">学年</a> <a href="/tags/978/" title="地区" class="c1" target="_blank">地区</a> ……8′

17解: <a href="/tags/4/" title="测试" class="c1" target="_blank">测试</a> <a href="/tags/54/" title="试卷" class="c1" target="_blank">试卷</a> <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/208/" title="学期" class="c1" target="_blank">学期</a> <a href="/tags/255/" title="学年" class="c1" target="_blank">学年</a> <a href="/tags/978/" title="地区" class="c1" target="_blank">地区</a>

去分母  <a href="/tags/4/" title="测试" class="c1" target="_blank">测试</a> <a href="/tags/54/" title="试卷" class="c1" target="_blank">试卷</a> <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/208/" title="学期" class="c1" target="_blank">学期</a> <a href="/tags/255/" title="学年" class="c1" target="_blank">学年</a> <a href="/tags/978/" title="地区" class="c1" target="_blank">地区</a>

合并  <a href="/tags/4/" title="测试" class="c1" target="_blank">测试</a> <a href="/tags/54/" title="试卷" class="c1" target="_blank">试卷</a> <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/208/" title="学期" class="c1" target="_blank">学期</a> <a href="/tags/255/" title="学年" class="c1" target="_blank">学年</a> <a href="/tags/978/" title="地区" class="c1" target="_blank">地区</a>

系数化为1  <a href="/tags/4/" title="测试" class="c1" target="_blank">测试</a> <a href="/tags/54/" title="试卷" class="c1" target="_blank">试卷</a> <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/208/" title="学期" class="c1" target="_blank">学期</a> <a href="/tags/255/" title="学年" class="c1" target="_blank">学年</a> <a href="/tags/978/" title="地区" class="c1" target="_blank">地区</a> ……6′

经检验 <a href="/tags/4/" title="测试" class="c1" target="_blank">测试</a> <a href="/tags/54/" title="试卷" class="c1" target="_blank">试卷</a> <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/208/" title="学期" class="c1" target="_blank">学期</a> <a href="/tags/255/" title="学年" class="c1" target="_blank">学年</a> <a href="/tags/978/" title="地区" class="c1" target="_blank">地区</a> 是原方程的解。 ……8′

18a2(x-y)2+2a(x-y)3+(x-y)4

=(x-y)2[a2+2a(x-y)+(x-y)2] ……4

=(x-y)2(a+x-y)2 ……8

19解:原式= <a href="/tags/4/" title="测试" class="c1" target="_blank">测试</a> <a href="/tags/54/" title="试卷" class="c1" target="_blank">试卷</a> <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/208/" title="学期" class="c1" target="_blank">学期</a> <a href="/tags/255/" title="学年" class="c1" target="_blank">学年</a> <a href="/tags/978/" title="地区" class="c1" target="_blank">地区</a>

= <a href="/tags/4/" title="测试" class="c1" target="_blank">测试</a> <a href="/tags/54/" title="试卷" class="c1" target="_blank">试卷</a> <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/208/" title="学期" class="c1" target="_blank">学期</a> <a href="/tags/255/" title="学年" class="c1" target="_blank">学年</a> <a href="/tags/978/" title="地区" class="c1" target="_blank">地区</a>

= <a href="/tags/4/" title="测试" class="c1" target="_blank">测试</a> <a href="/tags/54/" title="试卷" class="c1" target="_blank">试卷</a> <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/208/" title="学期" class="c1" target="_blank">学期</a> <a href="/tags/255/" title="学年" class="c1" target="_blank">学年</a> <a href="/tags/978/" title="地区" class="c1" target="_blank">地区</a> ……6′

 <a href="/tags/4/" title="测试" class="c1" target="_blank">测试</a> <a href="/tags/54/" title="试卷" class="c1" target="_blank">试卷</a> <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/208/" title="学期" class="c1" target="_blank">学期</a> <a href="/tags/255/" title="学年" class="c1" target="_blank">学年</a> <a href="/tags/978/" title="地区" class="c1" target="_blank">地区</a> 代入得 <a href="/tags/4/" title="测试" class="c1" target="_blank">测试</a> <a href="/tags/54/" title="试卷" class="c1" target="_blank">试卷</a> <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/208/" title="学期" class="c1" target="_blank">学期</a> <a href="/tags/255/" title="学年" class="c1" target="_blank">学年</a> <a href="/tags/978/" title="地区" class="c1" target="_blank">地区</a> 。 ……8′

五、

20、解:(1 <a href="/tags/4/" title="测试" class="c1" target="_blank">测试</a> <a href="/tags/54/" title="试卷" class="c1" target="_blank">试卷</a> <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/208/" title="学期" class="c1" target="_blank">学期</a> <a href="/tags/255/" title="学年" class="c1" target="_blank">学年</a> <a href="/tags/978/" title="地区" class="c1" target="_blank">地区</a> ……4′

2 <a href="/tags/4/" title="测试" class="c1" target="_blank">测试</a> <a href="/tags/54/" title="试卷" class="c1" target="_blank">试卷</a> <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/208/" title="学期" class="c1" target="_blank">学期</a> <a href="/tags/255/" title="学年" class="c1" target="_blank">学年</a> <a href="/tags/978/" title="地区" class="c1" target="_blank">地区</a> ……10′


21、解:∵∠COF60°

∴∠COE120° ……4′

又∵∠AOE2∠AOC

∴∠AOC40° ……8′

∴∠BOD=∠AOC40° ……10′


六、

22、解:∵ EF⊥BCAD⊥BC

 <a href="/tags/4/" title="测试" class="c1" target="_blank">测试</a> <a href="/tags/54/" title="试卷" class="c1" target="_blank">试卷</a> <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/208/" title="学期" class="c1" target="_blank">学期</a> <a href="/tags/255/" title="学年" class="c1" target="_blank">学年</a> <a href="/tags/978/" title="地区" class="c1" target="_blank">地区</a> AD∥EF ……2′

∴ ∠2=∠3 ……5′

又∵∠1=∠2

∴∠1=∠3 ……7′

AB∥DG ……10′

AC⊥AB

DG⊥AC ……12′

七、

23解:1)设商场第一次购进 <a href="/tags/4/" title="测试" class="c1" target="_blank">测试</a> <a href="/tags/54/" title="试卷" class="c1" target="_blank">试卷</a> <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/208/" title="学期" class="c1" target="_blank">学期</a> <a href="/tags/255/" title="学年" class="c1" target="_blank">学年</a> <a href="/tags/978/" title="地区" class="c1" target="_blank">地区</a> 套运动服,由题意得:

 <a href="/tags/4/" title="测试" class="c1" target="_blank">测试</a> <a href="/tags/54/" title="试卷" class="c1" target="_blank">试卷</a> <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/208/" title="学期" class="c1" target="_blank">学期</a> <a href="/tags/255/" title="学年" class="c1" target="_blank">学年</a> <a href="/tags/978/" title="地区" class="c1" target="_blank">地区</a> , ……2′

解这个方程,得 <a href="/tags/4/" title="测试" class="c1" target="_blank">测试</a> <a href="/tags/54/" title="试卷" class="c1" target="_blank">试卷</a> <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/208/" title="学期" class="c1" target="_blank">学期</a> <a href="/tags/255/" title="学年" class="c1" target="_blank">学年</a> <a href="/tags/978/" title="地区" class="c1" target="_blank">地区</a>

经检验, <a href="/tags/4/" title="测试" class="c1" target="_blank">测试</a> <a href="/tags/54/" title="试卷" class="c1" target="_blank">试卷</a> <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/208/" title="学期" class="c1" target="_blank">学期</a> <a href="/tags/255/" title="学年" class="c1" target="_blank">学年</a> <a href="/tags/978/" title="地区" class="c1" target="_blank">地区</a> 是所列方程的根。 ……4′

 <a href="/tags/4/" title="测试" class="c1" target="_blank">测试</a> <a href="/tags/54/" title="试卷" class="c1" target="_blank">试卷</a> <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/208/" title="学期" class="c1" target="_blank">学期</a> <a href="/tags/255/" title="学年" class="c1" target="_blank">学年</a> <a href="/tags/978/" title="地区" class="c1" target="_blank">地区</a>

所以商场两次共购进这种运动服600套。 ……6′

2)设每套运动服的售价为 <a href="/tags/4/" title="测试" class="c1" target="_blank">测试</a> <a href="/tags/54/" title="试卷" class="c1" target="_blank">试卷</a> <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/208/" title="学期" class="c1" target="_blank">学期</a> <a href="/tags/255/" title="学年" class="c1" target="_blank">学年</a> <a href="/tags/978/" title="地区" class="c1" target="_blank">地区</a> 元,由题意得:

 <a href="/tags/4/" title="测试" class="c1" target="_blank">测试</a> <a href="/tags/54/" title="试卷" class="c1" target="_blank">试卷</a> <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/208/" title="学期" class="c1" target="_blank">学期</a> <a href="/tags/255/" title="学年" class="c1" target="_blank">学年</a> <a href="/tags/978/" title="地区" class="c1" target="_blank">地区</a> , ……10′

解这个不等式,得 <a href="/tags/4/" title="测试" class="c1" target="_blank">测试</a> <a href="/tags/54/" title="试卷" class="c1" target="_blank">试卷</a> <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/208/" title="学期" class="c1" target="_blank">学期</a> <a href="/tags/255/" title="学年" class="c1" target="_blank">学年</a> <a href="/tags/978/" title="地区" class="c1" target="_blank">地区</a> , ……12′

所以每套运动服的售价至少是200元。 ……14′