Hello all. I'm trying to solve an equation of the form:

$\displaystyle \frac{dx}{dy}=\frac{x^2 + y^2}{3xy}$

I'm thinking that I can use seperable variable on it, but am stumped as to how to get it into that form. A colleague has suggested using substitution, but sadly my hours of trawling through textbooks/internet has left me feeling frustrated and uncertain. Any pointers where to look would be greatly appreciated.

Thanks