=(x-1)/(x-2)(x-1)-(x+1)/(x+2)(x+1)-x²/(x+2)(x-2)
=1/(x-2)-1/(x+2)-x²/(x+2)(x-2)
=[(x+2)-(x-2)-x²]/(x+2)(x-2)
=(4-x²)/(x²-4)
=-1