问题描述: 数学题“1/4+1/28+1/70+1/130”怎样计算? 1个回答 分类:数学 2014-12-09 问题解答: 我来补答 原式=1/(1*4)+1/(4*7)+1/(7*10)+1/(10*13) =(1/3)*(1-1/4)+(1/3)*(1/4-1/7)+(1/3)*(1/7-1/10)+(1/3)*(1/10-1/13) =(1/3)*(1-1/4+1/4-1/7+1/7-1/10+1/10-1/13) =(1/3)*(1-1/13) =4/13. 展开全文阅读