1) it's not exact, I know that
2) I tried turning it into an exact equation using Euler's multiplicating factor (not sure this is the right word in English), but couldn't find the factor
3) tried the y/x=v substitution and ended up with:
xv + 1 + xv^3 - v^3 + x^2v^2v' - xv^2v' = 0
and I've no idea how to separate the x and v here
4) tried separating the variables and ended up with this:
what do I do?