先化简再求值x²-x/（x+1）×x²-1/（x²-2x+1）先化简再求值：x²-x/（x_数学解答

先化简再求值x²-x/（x+1）×x²-1/（x²-2x+1）
先化简再求值：x²-x/（x+1）×x²-1/（x²-2x+1）,其中x满足x²-3x+2=0

人气：449 ℃　时间：2020-02-15 08:50:43

解答

x²-3x+2=(x-1)(x-2)=0
x=1,x=2
x=1,分母x²-2x+1=0,舍去
所以x=2
原式=[x(x-1)/(x+1)][(x+1)(x-1)/(x-1)²]
=x(x-1)(x+1)(x-1)/[(x+1)(x-1)²]
=x
=2