问题描述: (1+1/2+1/3+1/4+1/5)*(1/3+1/4+1)-(1+1/3+1/4)*(1/2+1/3+1/4+1/5) 1个回答 分类:数学 2014-10-11 问题解答: 我来补答 设 1/2+1/3+1/4+1/5 = A(1+1/3+1/4) = B(1+1/2+1/3+1/4+1/5)*(1/3+1/4+1)-(1+1/3+1/4)*(1/2+1/3+1/4+1/5)= 1 * B + A * B - B * A= 1 * B= (1+1/3+1/4)= 19/12 展开全文阅读