(1)(m^2+n^2/m-n) +2mn/n-m
问题描述：
(1)(m^2+n^2/m-n) +2mn/n-m
(2)(x^+2x+1/x^2-x)乘(x/x+1)-(1/x-1)
答
(1)=(M^2+n^2/m-n)-(2mn/m-n)
=m^2-2mn+n^2/m-n
=(m-n) ^2/m-n
=m-n
(2)=((x+1) ^2/x(x+1))×(x/x+1)- (1/x-1)
=(x+1/x-1)-1/x-1
=x/x-1