differential equation of cheese

(y+x) dy/dx = y       use y=xu to solve

save me from evil problem lords!

(ux + x)(u + x du/dx) = xu
x(u+1)(u + x du/dx) = xu
(u+1)(u+x du/dx) = u
(u + x du/dx) = u/(u+1)
x du/dx = u/(u+1) - u
x du/dx = (u - u^2 - u)/(u+1)
1/x dx = (u+1)/(-u^2) du