问题描述: (1/3-8/12+9/20-11/30+13/42-15/56)*2^3-(-2)^100*0.25^50等于? 1个回答 分类:数学 2014-10-19 问题解答: 我来补答 应该是7/12不是8/121/3-7/12+9/20-11/30+13/42-15/56=1/3-(3+4)/12+(4+5)/20-(5+6)/30+(6+7)/42-(7+8)/56=1/3-1/3-1/4+1/4+1/5-1/5-1/6+1/6+1/7-1/7-1/8=-1/8原式=(1/3-8/12+9/20-11/30+13/42-15/56)*2^3-(-2)^100*0.25^50=(-1/8)*8-(4)^50*(1/4)^50=-1-(4*1/4)^50=-1-1=-2 展开全文阅读