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【323562】2023七年级数学上册 第2章 有理数2.13有理数的混合运算课时练习 (新版)华东师

时间:2025-01-15 19:23:27 作者: 字数:2881字
简介:


有理数的混合运算

(30分钟 50)

一、选择题(每小题4,12)

1.计算:-(-2)2+(-1)2÷(-1 <a href="/tags/16/" title="课时" class="c1" target="_blank">课时</a> <a href="/tags/45/" title="混合" class="c1" target="_blank">混合</a> <a href="/tags/48/" title="练习" class="c1" target="_blank">练习</a> <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/848/" title="华东" class="c1" target="_blank">华东</a> <a href="/tags/852/" title="有理数" class="c1" target="_blank">有理数</a> )-(-2)2×(- <a href="/tags/16/" title="课时" class="c1" target="_blank">课时</a> <a href="/tags/45/" title="混合" class="c1" target="_blank">混合</a> <a href="/tags/48/" title="练习" class="c1" target="_blank">练习</a> <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/848/" title="华东" class="c1" target="_blank">华东</a> <a href="/tags/852/" title="有理数" class="c1" target="_blank">有理数</a> )的结果是 (  )

A.4 <a href="/tags/16/" title="课时" class="c1" target="_blank">课时</a> <a href="/tags/45/" title="混合" class="c1" target="_blank">混合</a> <a href="/tags/48/" title="练习" class="c1" target="_blank">练习</a> <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/848/" title="华东" class="c1" target="_blank">华东</a> <a href="/tags/852/" title="有理数" class="c1" target="_blank">有理数</a> B.-3 <a href="/tags/16/" title="课时" class="c1" target="_blank">课时</a> <a href="/tags/45/" title="混合" class="c1" target="_blank">混合</a> <a href="/tags/48/" title="练习" class="c1" target="_blank">练习</a> <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/848/" title="华东" class="c1" target="_blank">华东</a> <a href="/tags/852/" title="有理数" class="c1" target="_blank">有理数</a> C.-2 <a href="/tags/16/" title="课时" class="c1" target="_blank">课时</a> <a href="/tags/45/" title="混合" class="c1" target="_blank">混合</a> <a href="/tags/48/" title="练习" class="c1" target="_blank">练习</a> <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/848/" title="华东" class="c1" target="_blank">华东</a> <a href="/tags/852/" title="有理数" class="c1" target="_blank">有理数</a> D.-4 <a href="/tags/16/" title="课时" class="c1" target="_blank">课时</a> <a href="/tags/45/" title="混合" class="c1" target="_blank">混合</a> <a href="/tags/48/" title="练习" class="c1" target="_blank">练习</a> <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/848/" title="华东" class="c1" target="_blank">华东</a> <a href="/tags/852/" title="有理数" class="c1" target="_blank">有理数</a>

2.下列各式中计算正确的是 (  )

A.6÷(2×3)=6÷2×3=3×3=9

B.24-22÷20=2 <a href="/tags/16/" title="课时" class="c1" target="_blank">课时</a> <a href="/tags/45/" title="混合" class="c1" target="_blank">混合</a> <a href="/tags/48/" title="练习" class="c1" target="_blank">练习</a> <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/848/" title="华东" class="c1" target="_blank">华东</a> <a href="/tags/852/" title="有理数" class="c1" target="_blank">有理数</a> 0÷20=1

C.-22+(-7)÷(- <a href="/tags/16/" title="课时" class="c1" target="_blank">课时</a> <a href="/tags/45/" title="混合" class="c1" target="_blank">混合</a> <a href="/tags/48/" title="练习" class="c1" target="_blank">练习</a> <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/848/" title="华东" class="c1" target="_blank">华东</a> <a href="/tags/852/" title="有理数" class="c1" target="_blank">有理数</a> )=-4+7× <a href="/tags/16/" title="课时" class="c1" target="_blank">课时</a> <a href="/tags/45/" title="混合" class="c1" target="_blank">混合</a> <a href="/tags/48/" title="练习" class="c1" target="_blank">练习</a> <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/848/" title="华东" class="c1" target="_blank">华东</a> <a href="/tags/852/" title="有理数" class="c1" target="_blank">有理数</a> =-4+4=0

D.3÷( <a href="/tags/16/" title="课时" class="c1" target="_blank">课时</a> <a href="/tags/45/" title="混合" class="c1" target="_blank">混合</a> <a href="/tags/48/" title="练习" class="c1" target="_blank">练习</a> <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/848/" title="华东" class="c1" target="_blank">华东</a> <a href="/tags/852/" title="有理数" class="c1" target="_blank">有理数</a> - <a href="/tags/16/" title="课时" class="c1" target="_blank">课时</a> <a href="/tags/45/" title="混合" class="c1" target="_blank">混合</a> <a href="/tags/48/" title="练习" class="c1" target="_blank">练习</a> <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/848/" title="华东" class="c1" target="_blank">华东</a> <a href="/tags/852/" title="有理数" class="c1" target="_blank">有理数</a> )=3÷ <a href="/tags/16/" title="课时" class="c1" target="_blank">课时</a> <a href="/tags/45/" title="混合" class="c1" target="_blank">混合</a> <a href="/tags/48/" title="练习" class="c1" target="_blank">练习</a> <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/848/" title="华东" class="c1" target="_blank">华东</a> <a href="/tags/852/" title="有理数" class="c1" target="_blank">有理数</a> -3÷ <a href="/tags/16/" title="课时" class="c1" target="_blank">课时</a> <a href="/tags/45/" title="混合" class="c1" target="_blank">混合</a> <a href="/tags/48/" title="练习" class="c1" target="_blank">练习</a> <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/848/" title="华东" class="c1" target="_blank">华东</a> <a href="/tags/852/" title="有理数" class="c1" target="_blank">有理数</a> =9-6=3

3.(滨州中考)1+2+22+23+…+22012的值,可令S=1+2+22+23+…+22012,2S=2+22+23+24+…+22013,因此2S-S=22013-1,仿照以上推理,计算出1+5+52+53+…+52012的值为 (  )

A.52012-1 B.52013-1 C. <a href="/tags/16/" title="课时" class="c1" target="_blank">课时</a> <a href="/tags/45/" title="混合" class="c1" target="_blank">混合</a> <a href="/tags/48/" title="练习" class="c1" target="_blank">练习</a> <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/848/" title="华东" class="c1" target="_blank">华东</a> <a href="/tags/852/" title="有理数" class="c1" target="_blank">有理数</a> D. <a href="/tags/16/" title="课时" class="c1" target="_blank">课时</a> <a href="/tags/45/" title="混合" class="c1" target="_blank">混合</a> <a href="/tags/48/" title="练习" class="c1" target="_blank">练习</a> <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/848/" title="华东" class="c1" target="_blank">华东</a> <a href="/tags/852/" title="有理数" class="c1" target="_blank">有理数</a>

二、填空题(每小题4,12)

4.对于任意有理数x,经过以下运算过程,x=-6,运算结果是________.

 <a href="/tags/16/" title="课时" class="c1" target="_blank">课时</a> <a href="/tags/45/" title="混合" class="c1" target="_blank">混合</a> <a href="/tags/48/" title="练习" class="c1" target="_blank">练习</a> <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/848/" title="华东" class="c1" target="_blank">华东</a> <a href="/tags/852/" title="有理数" class="c1" target="_blank">有理数</a>

5.定义a※b=a2-ab,(1※2)※3=________.

6.(株洲中考)(x1,y1)·(x2,y2)=x1x2+y1y2,(4,5)·(6,8)=________.

三、解答题(26)

7.(8)计算:(1)-32+(-2 <a href="/tags/16/" title="课时" class="c1" target="_blank">课时</a> <a href="/tags/45/" title="混合" class="c1" target="_blank">混合</a> <a href="/tags/48/" title="练习" class="c1" target="_blank">练习</a> <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/848/" title="华东" class="c1" target="_blank">华东</a> <a href="/tags/852/" title="有理数" class="c1" target="_blank">有理数</a> )2-(-2)3+|-22|.

(2)-23 <a href="/tags/16/" title="课时" class="c1" target="_blank">课时</a> <a href="/tags/45/" title="混合" class="c1" target="_blank">混合</a> <a href="/tags/48/" title="练习" class="c1" target="_blank">练习</a> <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/848/" title="华东" class="c1" target="_blank">华东</a> <a href="/tags/852/" title="有理数" class="c1" target="_blank">有理数</a> -[(-3)2-22× <a href="/tags/16/" title="课时" class="c1" target="_blank">课时</a> <a href="/tags/45/" title="混合" class="c1" target="_blank">混合</a> <a href="/tags/48/" title="练习" class="c1" target="_blank">练习</a> <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/848/" title="华东" class="c1" target="_blank">华东</a> <a href="/tags/852/" title="有理数" class="c1" target="_blank">有理数</a> -8.5]÷(- <a href="/tags/16/" title="课时" class="c1" target="_blank">课时</a> <a href="/tags/45/" title="混合" class="c1" target="_blank">混合</a> <a href="/tags/48/" title="练习" class="c1" target="_blank">练习</a> <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/848/" title="华东" class="c1" target="_blank">华东</a> <a href="/tags/852/" title="有理数" class="c1" target="_blank">有理数</a> )2.

8.(8)1开始,将连续的奇数相加,和的情况有如下规律:

1=12;1+3=22;1+3+5=32;1+ <a href="/tags/16/" title="课时" class="c1" target="_blank">课时</a> <a href="/tags/45/" title="混合" class="c1" target="_blank">混合</a> <a href="/tags/48/" title="练习" class="c1" target="_blank">练习</a> <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/848/" title="华东" class="c1" target="_blank">华东</a> <a href="/tags/852/" title="有理数" class="c1" target="_blank">有理数</a> 3+5+7=42;1+3+5+7+9=52;…按此规律, <a href="/tags/16/" title="课时" class="c1" target="_blank">课时</a> <a href="/tags/45/" title="混合" class="c1" target="_blank">混合</a> <a href="/tags/48/" title="练习" class="c1" target="_blank">练习</a> <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/848/" title="华东" class="c1" target="_blank">华东</a> <a href="/tags/852/" title="有理数" class="c1" target="_blank">有理数</a> 你猜想从1开始,将前10个奇数(即当最后一个奇数是19)相加,其和是多少?

【拓展延伸】

9.(10)(1)计算:①2-1;②22-2-1;③23-22-2-1;④24-23-22-2-1;⑤25-24-23-22-2-1.

(2)根据上面的计算结果猜想:

22014-22013-22012-…-22-2-1的值为________;

2n-2n-1-2n-2-…-22-2-1的值为________.

(3)根据上面猜想的结论求212-211-210-29-28-27-26的值.















答案解析

1.【解析】选B.-(-2)2+(-1)2÷(-1 <a href="/tags/16/" title="课时" class="c1" target="_blank">课时</a> <a href="/tags/45/" title="混合" class="c1" target="_blank">混合</a> <a href="/tags/48/" title="练习" class="c1" target="_blank">练习</a> <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/848/" title="华东" class="c1" target="_blank">华东</a> <a href="/tags/852/" title="有理数" class="c1" target="_blank">有理数</a> )-(-2)2×(- <a href="/tags/16/" title="课时" class="c1" target="_blank">课时</a> <a href="/tags/45/" title="混合" class="c1" target="_blank">混合</a> <a href="/tags/48/" title="练习" class="c1" target="_blank">练习</a> <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/848/" title="华东" class="c1" target="_blank">华东</a> <a href="/tags/852/" title="有理数" class="c1" target="_blank">有理数</a> )=-4+1×(- <a href="/tags/16/" title="课时" class="c1" target="_blank">课时</a> <a href="/tags/45/" title="混合" class="c1" target="_blank">混合</a> <a href="/tags/48/" title="练习" class="c1" target="_blank">练习</a> <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/848/" title="华东" class="c1" target="_blank">华东</a> <a href="/tags/852/" title="有理数" class="c1" target="_blank">有理数</a> )+1=-3 <a href="/tags/16/" title="课时" class="c1" target="_blank">课时</a> <a href="/tags/45/" title="混合" class="c1" target="_blank">混合</a> <a href="/tags/48/" title="练习" class="c1" target="_blank">练习</a> <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/848/" title="华东" class="c1" target="_blank">华东</a> <a href="/tags/852/" title="有理数" class="c1" target="_blank">有理数</a> .

2.【解析】选C.

6÷(2×3)=6÷6=1;24-22÷20=24-4÷20=24- <a href="/tags/16/" title="课时" class="c1" target="_blank">课时</a> <a href="/tags/45/" title="混合" class="c1" target="_blank">混合</a> <a href="/tags/48/" title="练习" class="c1" target="_blank">练习</a> <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/848/" title="华东" class="c1" target="_blank">华东</a> <a href="/tags/852/" title="有理数" class="c1" target="_blank">有理数</a> =23 <a href="/tags/16/" title="课时" class="c1" target="_blank">课时</a> <a href="/tags/45/" title="混合" class="c1" target="_blank">混合</a> <a href="/tags/48/" title="练习" class="c1" target="_blank">练习</a> <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/848/" title="华东" class="c1" target="_blank">华东</a> <a href="/tags/852/" title="有理数" class="c1" target="_blank">有理数</a> ;-22+(-7)÷(- <a href="/tags/16/" title="课时" class="c1" target="_blank">课时</a> <a href="/tags/45/" title="混合" class="c1" target="_blank">混合</a> <a href="/tags/48/" title="练习" class="c1" target="_blank">练习</a> <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/848/" title="华东" class="c1" target="_blank">华东</a> <a href="/tags/852/" title="有理数" class="c1" target="_blank">有理数</a> )=-4+7× <a href="/tags/16/" title="课时" class="c1" target="_blank">课时</a> <a href="/tags/45/" title="混合" class="c1" target="_blank">混合</a> <a href="/tags/48/" title="练习" class="c1" target="_blank">练习</a> <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/848/" title="华东" class="c1" target="_blank">华东</a> <a href="/tags/852/" title="有理数" class="c1" target="_blank">有理数</a> =-4+4=0;3÷( <a href="/tags/16/" title="课时" class="c1" target="_blank">课时</a> <a href="/tags/45/" title="混合" class="c1" target="_blank">混合</a> <a href="/tags/48/" title="练习" class="c1" target="_blank">练习</a> <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/848/" title="华东" class="c1" target="_blank">华东</a> <a href="/tags/852/" title="有理数" class="c1" target="_blank">有理数</a> - <a href="/tags/16/" title="课时" class="c1" target="_blank">课时</a> <a href="/tags/45/" title="混合" class="c1" target="_blank">混合</a> <a href="/tags/48/" title="练习" class="c1" target="_blank">练习</a> <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/848/" title="华东" class="c1" target="_blank">华东</a> <a href="/tags/852/" title="有理数" class="c1" target="_blank">有理数</a> )=3÷( <a href="/tags/16/" title="课时" class="c1" target="_blank">课时</a> <a href="/tags/45/" title="混合" class="c1" target="_blank">混合</a> <a href="/tags/48/" title="练习" class="c1" target="_blank">练习</a> <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/848/" title="华东" class="c1" target="_blank">华东</a> <a href="/tags/852/" title="有理数" class="c1" target="_blank">有理数</a> - <a href="/tags/16/" title="课时" class="c1" target="_blank">课时</a> <a href="/tags/45/" title="混合" class="c1" target="_blank">混合</a> <a href="/tags/48/" title="练习" class="c1" target="_blank">练习</a> <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/848/" title="华东" class="c1" target="_blank">华东</a> <a href="/tags/852/" title="有理数" class="c1" target="_blank">有理数</a> )=3÷(- <a href="/tags/16/" title="课时" class="c1" target="_blank">课时</a> <a href="/tags/45/" title="混合" class="c1" target="_blank">混合</a> <a href="/tags/48/" title="练习" class="c1" target="_blank">练习</a> <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/848/" title="华东" class="c1" target="_blank">华东</a> <a href="/tags/852/" title="有理数" class="c1" target="_blank">有理数</a> )=3×(-6)=-18.

3.【解析】选C.S=1+5+52+53+…+52012,5S=5+52+53+54+…+52013,因此5S-S=52013-1,所以S= <a href="/tags/16/" title="课时" class="c1" target="_blank">课时</a> <a href="/tags/45/" title="混合" class="c1" target="_blank">混合</a> <a href="/tags/48/" title="练习" class="c1" target="_blank">练习</a> <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/848/" title="华东" class="c1" target="_blank">华东</a> <a href="/tags/852/" title="有理数" class="c1" target="_blank">有理数</a> .

4.【解析】根据运算框图可知,[(-6 <a href="/tags/16/" title="课时" class="c1" target="_blank">课时</a> <a href="/tags/45/" title="混合" class="c1" target="_blank">混合</a> <a href="/tags/48/" title="练习" class="c1" target="_blank">练习</a> <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/848/" title="华东" class="c1" target="_blank">华东</a> <a href="/tags/852/" title="有理数" class="c1" target="_blank">有理数</a> )+3]2× <a href="/tags/16/" title="课时" class="c1" target="_blank">课时</a> <a href="/tags/45/" title="混合" class="c1" target="_blank">混合</a> <a href="/tags/48/" title="练习" class="c1" target="_blank">练习</a> <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/848/" title="华东" class="c1" target="_blank">华东</a> <a href="/tags/852/" title="有理数" class="c1" target="_blank">有理数</a> =(-3)2× <a href="/tags/16/" title="课时" class="c1" target="_blank">课时</a> <a href="/tags/45/" title="混合" class="c1" target="_blank">混合</a> <a href="/tags/48/" title="练习" class="c1" target="_blank">练习</a> <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/848/" title="华东" class="c1" target="_blank">华东</a> <a href="/tags/852/" title="有理数" class="c1" target="_blank">有理数</a> =9× <a href="/tags/16/" title="课时" class="c1" target="_blank">课时</a> <a href="/tags/45/" title="混合" class="c1" target="_blank">混合</a> <a href="/tags/48/" title="练习" class="c1" target="_blank">练习</a> <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/848/" title="华东" class="c1" target="_blank">华东</a> <a href="/tags/852/" title="有理数" class="c1" target="_blank">有理数</a> =3.

答案:3

 <a href="/tags/16/" title="课时" class="c1" target="_blank">课时</a> <a href="/tags/45/" title="混合" class="c1" target="_blank">混合</a> <a href="/tags/48/" title="练习" class="c1" target="_blank">练习</a> <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/848/" title="华东" class="c1" target="_blank">华东</a> <a href="/tags/852/" title="有理数" class="c1" target="_blank">有理数</a> 变式训练】如图是一个数值转换机.若输入数3,则输出数是________.

输入数(  )2-1(  )2 <a href="/tags/16/" title="课时" class="c1" target="_blank">课时</a> <a href="/tags/45/" title="混合" class="c1" target="_blank">混合</a> <a href="/tags/48/" title="练习" class="c1" target="_blank">练习</a> <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/848/" title="华东" class="c1" target="_blank">华东</a> <a href="/tags/852/" title="有理数" class="c1" target="_blank">有理数</a> +1输出数

【解析】(32-1)2+1=(9-1)2+1 <a href="/tags/16/" title="课时" class="c1" target="_blank">课时</a> <a href="/tags/45/" title="混合" class="c1" target="_blank">混合</a> <a href="/tags/48/" title="练习" class="c1" target="_blank">练习</a> <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/848/" title="华东" class="c1" target="_blank">华东</a> <a href="/tags/852/" title="有理数" class="c1" target="_blank">有理数</a> =82+1=65,即输出数是65. <a href="/tags/16/" title="课时" class="c1" target="_blank">课时</a> <a href="/tags/45/" title="混合" class="c1" target="_blank">混合</a> <a href="/tags/48/" title="练习" class="c1" target="_blank">练习</a> <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/848/" title="华东" class="c1" target="_blank">华东</a> <a href="/tags/852/" title="有理数" class="c1" target="_blank">有理数</a>

答案:65

5.【解析】根据题意可知,(1※2)※3=(12-1×2)※3=(-1)※3=(-1)2-(-1)×3=1+3=4.

答案:4

6.【解析】(4,5)·(6,8)=4×6+5×8=24+40=64.

答案:64

7.【解析】(1)原式=-9+ <a href="/tags/16/" title="课时" class="c1" target="_blank">课时</a> <a href="/tags/45/" title="混合" class="c1" target="_blank">混合</a> <a href="/tags/48/" title="练习" class="c1" target="_blank">练习</a> <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/848/" title="华东" class="c1" target="_blank">华东</a> <a href="/tags/852/" title="有理数" class="c1" target="_blank">有理数</a> -(-8)+|-4|

=-9+ <a href="/tags/16/" title="课时" class="c1" target="_blank">课时</a> <a href="/tags/45/" title="混合" class="c1" target="_blank">混合</a> <a href="/tags/48/" title="练习" class="c1" target="_blank">练习</a> <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/848/" title="华东" class="c1" target="_blank">华东</a> <a href="/tags/852/" title="有理数" class="c1" target="_blank">有理数</a> +8+4=9 <a href="/tags/16/" title="课时" class="c1" target="_blank">课时</a> <a href="/tags/45/" title="混合" class="c1" target="_blank">混合</a> <a href="/tags/48/" title="练习" class="c1" target="_blank">练习</a> <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/848/" title="华东" class="c1" target="_blank">华东</a> <a href="/tags/852/" title="有理数" class="c1" target="_blank">有理数</a> .

(2)原式=-8-(9-4× <a href="/tags/16/" title="课时" class="c1" target="_blank">课时</a> <a href="/tags/45/" title="混合" class="c1" target="_blank">混合</a> <a href="/tags/48/" title="练习" class="c1" target="_blank">练习</a> <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/848/" title="华东" class="c1" target="_blank">华东</a> <a href="/tags/852/" title="有理数" class="c1" target="_blank">有理数</a> -8.5)×4

=-8-(-0.5)×4=-6.

8.【解析】观察等式两边的特征,可以看到等式左边是几个连续奇数的和,右边是左边奇数“个数”的平方,于是可得前10个奇数的和应为102=100.

 <a href="/tags/16/" title="课时" class="c1" target="_blank">课时</a> <a href="/tags/45/" title="混合" class="c1" target="_blank">混合</a> <a href="/tags/48/" title="练习" class="c1" target="_blank">练习</a> <a href="/tags/55/" title="数学" class="c1" target="_blank">数学</a> <a href="/tags/848/" title="华东" class="c1" target="_blank">华东</a> <a href="/tags/852/" title="有理数" class="c1" target="_blank">有理数</a> 1+3+5+7+…+19=102=100.

9.【解析】(1)①~⑤的值都是1.

(2)通过第(1)小题计算我们可以得出这样一个结论:2n中逐步减去2n-1,2n-2,…,22,2,1,所得的结果为1,因此①②这两小题的结果也是1.

(3)原式=212-211-…-25-24-23-22-2-1+(25+24+23+22+2+1)

=1+(25+24+23+22+2+1)=64.

3

《【323562】2023七年级数学上册 第2章 有理数2.13有理数的混合运算课时练习 (新版)华东师.doc》
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