原始=(x²-1-x-1)/(x-3)(x 1)(x-1)
=(x-2)(x 1)/(x-3)(x 1)(x-1)
=(x-2)/(x-3)(x-1)选项里没有啊看错题目了；
原式=(x²-1-（x+1)(x-3))/(x +1)(x-1)
=(x²-1-x²+2x+3)/(x+1)(x-1)
=2(x+1)/(x+1)(x-1)
=2/(x-1);