问题描述: |1/3-1/4|+|1/4-1/5|+.+|1/19-1/20|= 1个回答 分类:数学 2014-10-25 问题解答: 我来补答 |1/3-1/4|+|1/4-1/5|+.+|1/19-1/20|=(1/3-1/4)+(1/4-1/5)+(1/5-1/6)+...+(1/19-1/20)=1/3-1/4+1/4-1/5+1/5-1/6+...1/19-1/20=1/3-1/20=17/60 展开全文阅读