=[(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)不對(duì)哦。 哪個(gè)應(yīng)該是 （x²-1）/（x²-2x+1）， 不可以直接化為（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) 這個(gè)再和后面的通分這(x+1)²/(x+1)(x-1)哦。。謝謝啊。你們都很棒啊。請(qǐng)采納一下，謝謝