原式=1/(x+1)+(x-1)/(x-1)²+1/(x-1)²
=1/(x+1)+x/(x-1)²
=[(x-1)²+x(x-1)]/(x+1)(x-1)²
=(2x²-3x+1)/(x+1)(x-1)²
=(2x-1)(x-1)/(x+1)(x-1)²
=(2x-1)/(x²-1)
在右上角点击【评价】,然后就可以选择【满意,问题已经完美解决】了.好像错了