先化简,再约分 x²-x/x²-2x+1-x/x+1,其中x=2
问题描述：
先化简,再约分 x²-x/x²-2x+1-x/x+1,其中x=2
明天就交了~~~快点帮帮忙吧!
答
(x²-x)/(x²-2x+1)-x/(x+1)
=x(x-1)/(x-1)²-x/(x+1)
=x/(x-1)-x/(x+1)
=x(x+1)/(x-1)(x+1)-x(x-1)/(x-1)(x+1)
=(x²+x-x²+x)/(x-1)(x+1)
=2x/(x-1)(x+1)
将x=2代人上式得
原式=4/3