1+（n-m/m-2n）/(m^2-n^2/m^2-4mn+4n^2)

分类: 作业答案 • 2021-11-29 10:09:15

问题描述：

答

原式=1+ [（n-m）/(m-2n)]*[(m-2n)^2/(m+n)(m-n)]
=1+[-（m-n）/(m-2n)]*[(m-2n)^2/(m+n)(m-n)]
=1-(m-2n)/(m+n)
=(m+n-m+2n)/(m+n)
=3n/(m+n)