=[(x+1)(x-1)/(x-1)²-(x-1)/(x+1)]×(x-1)/x
=[(x+1)²-(x-1)²]/(x+1)(x-1)×(x-1)/x
=4x/(x+1)(x-1)×(x-1)/x
=4/(x+1)不对哦。 哪个应该是 （x²-1）/（x²-2x+1）， 不可以直接化为（x+1）（x-1）的啊。分子是x²-1分解因式得 (x+1)(x-1)分母是x²-2x+1 分解因式得(x-1)²,(x平方-2x+1)分之(x平方-1）=(x²-1)/(x²-2x+1)=(x+1)(x-1)/(x-1)²=(x+1)/(x-1) 这个再和后面的通分这(x+1)²/(x+1)(x-1)哦。。谢谢啊。你们都很棒啊。请采纳一下，谢谢