原式=[(x-1)/(x+2)]÷[(x-1)²/(x+2)(x-2)]+1/(x-1)
=[(x-1)(x+2)(x-2)]/](x+2)(x-1)²]+1/(x-1)
=(x-2)(x-1)+1/(x-1)
=(x-2+1)/(x-1)
=(x-1)/(x-1)
=1