用简便方法计算:①(-321625)×132-(12+23-34-1112)×(-24);②-999899×198;③(-3)×(-14)+0.25×24.5+(-512)×(-25%);④-989×(-9)+989×(-19)-(-989)×10.-数学
题文
用简便方法计算: ①(-32
②-99
③(-3)×(-
④-989×(-9)+989×(-19)-(-989)×10. |
答案
①(-32
=-1
=-1
=-13
②-99
=(-100+
=-100×198+
=-19800+2 =-19798; ③(-3)×(-
=
|