问题描述: (-1/2)-(-1/3)-(+1/4) 1个回答 分类:数学 2014-10-05 问题解答: 我来补答 (-1×1/2)+(-1/2×1/3)+(-1/3×1/4)+……+(-1/2004×1/2005)=-1/(1×2)+[-1/(2×3)]+[-1/(3×4)]+……+[-1/(2004×2005)]=-(1/1-1/2)+[-(1/2-1/3)]+[-(1/3-1/4)]+……+[-(1/2004-1/2005)]=-1+1/2-1/2+1/3-1/3+1/4-……-1/2004+1/2005=-1+1/2005=-2004/2005 展开全文阅读