先化简再求值:(x-2)/(x²-1)÷(2x+2)/(x²+2x+1)+1/(x-1),其中x=-1/2

问题描述:

先化简再求值:(x-2)/(x²-1)÷(2x+2)/(x²+2x+1)+1/(x-1),其中x=-1/2