A-A+
用简便方法计算:①(-321625)×132-(12+23-34-1112)×(-24);②
问题详情
用简便方法计算:
①(-32
②-99
③(-3)×(-
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