已知x-3y=0求2x+y/x²-2xy+y²·（x-y）的值

已知x-3y=0求2x+y/x²-2xy+y²·（x-y）的值
已知x-3y=0求2x+y/x²-2xy+y²·（x-y）的值

已知x-3y=0求2x+y/x²-2xy+y²·（x-y）的值
解
x-3y=0
x=3y
∴(2x+y)/(x²-2xy+y²)×(x-y)
=(2x+y)/(x-y)²×(x-y)
=(2x+y)/(x-y)
=(6y+y)/(3y-y)
=7/2

直接告诉我应该是0，具体推到就麻烦了