先化简,再求值

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先化简,再求值先化简,再求值 先化简,再求值x^2-3x+2=0(x-1)(x-2)=0x=1或2原式=x(x-1)/(x+1)*(x+1)(x-1)/(x-1)^2=x(x-1)/(x+1

先化简,再求值
先化简,再求值
 

先化简,再求值
x^2-3x+2=0
(x-1)(x-2)=0
x=1或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=2 (x=1时分母为0舍去)