已知mx=nx+m,且m-n不等于0化简(x-m)/n-(x-n)/m
问题描述：
已知mx=nx+m,且m-n不等于0化简(x-m)/n-(x-n)/m
答
mx=nx+m
(m-n)x=m
(x-m)/n-(x-n)/m
=x/n-m/n-x/m+n/m
=(x/n-x/m)+(n/m-m/n)
=(m-n)x/mn+(n/m-m/n)
=1/n+(n/m-m/n)
=(m-m^2+n^2)/mn