数学计算(要求过程写清)(1)-2²-(1-1/5×0.2)÷(-2)².(2)(1/3-5/7-2/5)×(-105)+2又13/14×(-7).
问题描述:
数学计算(要求过程写清)
(1)-2²-(1-1/5×0.2)÷(-2)².
(2)(1/3-5/7-2/5)×(-105)+2又13/14×(-7).
答
(1)-2²-(1-1/5×0.2)÷(-2)²=-4-(1-1/5×1/5)÷4=-4-(1-1/25)×1/4=-4-24/25×1/4=-4-6/25=106/25(2)(1/3-5/7-2/5)×(-105)+2又13/14×(-7)=(35/105-75/105-42/105)×(-105)+(51/14)×(-7)=...