问题描述: 简便方法计算:1/2+(-1/6)+(-1/12)+(-1/20)+(-1/30)+(-1/42) 1个回答 分类:数学 2014-10-24 问题解答: 我来补答 1/2+(-1/6)+(-1/12)+(-1/20)+(-1/30)+(-1/42)=1/2-1/6-1/12-1/20-1/30-1/42=1/2-(1/2-1/3)-(1/3-1/4)-(1/4-1/5)-(1/5-1/6)-(1/6-1/7)=1/2-1/2+1/3-1/3+1/4-1/4+1/5-1/5+1/6-1/6+1/7=1/7 展开全文阅读