now this is in the form of what my professor calls "exact" except we still need an integrating factor. They are quite difficult to find, for me, and honestly i cannot get this one to work out so im sorry but, i dont think i can help.
there is no one method of finding int factor but there are special cases
1)If 1/M (dN/dx - dM/dy) = f(y) then int factor is e^(integralf(y))
2) If 1/N (dM/dy- dN/dx) = f(x) tehn int factor is e^(integralf(x))
In your case 1) applies and 1/y^4 is the int factor