约分x^2-2x+1/1-x^2,刚才打错了、、、、

问题描述:

约分x^2-2x+1/1-x^2,刚才打错了、、、、

=(x-1)²/[-(x+1)(x-1)]
=-(x-1)/(x+1)
=(1-x)/(x+1)