原式=1-[8/(x+2)(x-2)][(x²+4x+4)/4x]/[(x-2)/2x]=1-[8/(x+2)(x-2)][(x+2)²/4x][2x/(x-2)]=1-4(x+2)/(x-2)²=(x²-4x+4-4x-8)/(x-2)²=(x²-8x-4)/(x²-4x+4)