A-A+

用简便方法计算:①(-321625)×132-(12+23-34-1112)×(-24);②

2022-08-15 11:51:30 问答库 阅读 205 次

问题详情

用简便方法计算:
①(-3216

25

)×1

32

-(1

2

+2

3

-3

4

-11

12

)×(-24);
②-9998

99

×198;
③(-3)×(-1

4

)+0.25×24.5+(-51

2

)×(-25%);
④-989×(-9)+989×(-19)-(-989)×10.

参考答案

①(-321625)×132-(12+23-34-1112)×(-24)
=-1150+12×24+23×24-34×24-1112×24
=-1150+12+16-18-22
=-13150;

②-999899×198
=(-100+199)×198
=-100×198+199×198
=-19800+2
=-19798;

③(-3)×(-14)+0.25×24.5+(-512)×(-25%)
=34+6.125+118
=814;

④-989×(-9)+989×(-19)-(-989)×10
=989×(9-19+10)
=989×0
=0.

考点:方法