问题描述： 计算：2/1-m-1/m-1.2x/x-y -y/y-x -y-2x/x-y.12/m²-9 -2/m-3 1个回答 分类：数学 2014-11-29 问题解答： 我来补答 2/(1-m)-1/(m-1)=2/(1-m)+1/(1-m)=3/(1-m)2x/(x-y )-y/(y-x) -(y-2x)/(x-y)2x/(x-y)+y/(x-y)-(y-2x)/(x-y)=(2x+y-y+2x)/(x-y)=4x/(x-y)12/(m²-9 )-2/(m-3)=12/(m-3)(m+3)-2/(m-3)=12/(m-3)(m+3)-2(m+3)/(m-3)(m+3)=(12-2m-6)/(m-3)(m+3)=(6-2m)/(m-3)(m+3)=-2(m-3)/(m-3)(m+3)=-2/(m+3) 展开全文阅读
