先化简再求值 x2-1分之x2-2x+1 +x+1分之1 其中,x=根号2-1
问题描述：
先化简再求值 x2-1分之x2-2x+1 +x+1分之1 其中,x=根号2-1
答
(x^2-2x+1)/(x^2-1)+1/(x+1)
=(x-1)^2/(x+1)(x-1) +1/(x+1)
=(x-1)/(x+1)+1/(x+1)
=x/(x+1)
=1-根2分之一