[(x-4)/(x-2)]+[4/(x的平方-4x+4)]÷[x/x-2]
=[(x-4)/(x-2)]+[4/(x-2)²]×（x-2）/x
=(x-4)/(x-2)+4/[x(x-2)]
=[x(x-4)+4]/[x(x-2)]
=[x²-4x+4]/[x(x-2)]
=(x-2)²/[x(x-2)]
=(x-2)/x
祝学习快乐!