问题描述： 1/2+1/6+1/12+1/20+1/30+1/42+1/56=?(要算式） 1个回答 分类：数学 2014-11-19 问题解答： 我来补答 1/2+1/6+1/12+1/20+1/30+1/42+1/56=1/(1*2)+1/(2*3)+1/(3*4)+1/(4*5)+1/(5*6)+1/(6*7)+1/(7*8)=1-1/2+1/2-1/3+1/3-1/4+1/4-1/5+1/5-1/6+1/6-1/7+1/7-1/8=1-1/8=7/8 展开全文阅读
