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