先化简,再求值x²-1分之x²+x－x-1分之x+1
问题描述：
先化简,再求值x²-1分之x²+x－x-1分之x+1
答
(x²+x)/(x²-1) - (x+1)/(x-1)
=x(x+1) / [(x+1)(x-1)] - (x+1)/(x-1)
= x/(x-1) - (x+1)/(x-1)
= - 1/(x-1)
代入x的值即可