问题描述: 若2m-n/m+2n=5,求3(2m-n)/m+2n-m+2n/2m-n+3的值 1个回答 分类:综合 2014-10-26 问题解答: 我来补答 (2m-n)/(m+2n)=5∴(m+2n)/(2m-n)=1/5∴3(2m-n)/m+2n-m+2n/2m-n+3=3×(2m-n)/(m+2n)+(m+2n)/(2m-n)+3=15+1/5+3=18又1/5 展开全文阅读