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