1/m-n,2/n^2-m^2,3n/2(m+n)通分
问题描述：
1/m-n,2/n^2-m^2,3n/2(m+n)通分
答
1/(m-n)=-1/(n-m)2/(n^2-m^2)=2/(n-m)(n+m)3n/[2(m+n)]公分母是2(m+n)(n-m)通分后1/(m-n)=-1/(n-m)=-2(m+n)/[2(m+n)(n-m)]2/(n^2-m^2)=2/(n-m)(n+m)=4/[2(m+n)(n-m)]3n/[2(m+n)]=3n(n-m)/[2(m+n)(n-m)]