原式=[(x+1)/(x-1)]-[(x²-2x)/(x²-1)]×[(x²+2x+1)/(x²-x-2)]
=[(x+1)/(x-1)]-{x(x-2)/[(x+1)(x-1)]}×[(x+1)²]/[(x+1)(x-2)]
=[(x+1)/(x-1)]-[x/(x-1)]
=(x+1-x)/(x-1)
=1/(x-1)