数学计算(要求过程写清)

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).
1个回答 分类:数学 2014-10-25

问题解答:

我来补答
(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)
=(-82/105)×(-105)-51/2
=82-51/2
=113/2
=56又1/2
 
 
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