（东营专版）2019年中考数学复习 第一章 数与式 第四节 二次根式要题随堂演练

二次根式

要题随堂演练

1．(2018·达州中考)二次根式2x＋4中的x的取值范围是( ) A．x＜－2 B．x≤－2 C．x＞－2

D．x≥－2

2．(2018·杭州中考)化简（－2）2的结果是( ) A．－2

B．±2

C．2

D．4

3．(2018·无锡中考)下列等式正确的是( ) A．(3)2

＝3 B.（－3）2

＝－3 C.33

＝3

D．(－3)2

＝－3

4．若x＋y－1＋(y＋2)2

＝0，则x－y的值为( ) A．－5

B．－1

C．1

D．5

5．(2017·广饶模拟)计算：3(3＋27)＝________．

6．(2018·广州中考)如图，数轴上点A表示的数为a，化简：a＋a2

－4a＋4＝________．

7．(2017·青岛中考)计算：(24＋1

6)×6＝________． 8．计算：113＋1

－sin 60°＋32×

8

.

参考答案

18．D ．解：原式＝2.C 3.A 3－4.D 15.12 36.2 37.13 13 32－2＋2＝2－2－2＋2＝2

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