原式=（x^2+xy）/（x^2-2xy+3y^2) x (3y-x)/(x-y) +(x^-1+y^-1)÷(x^-1-y^-1)
=- x(x+y)/（x-y) ^2 -(x+y)/（x-y)
= - 2/9 - 1/3
= - 5/9