Hello

I need help with the following ODE :

$\displaystyle \dfrac{dx}{(1-xy)^2}+\left[ y^2+\dfrac{x^2}{(1-xy)^2} \right]dy=0$

I multiplied both sides by $\displaystyle (1-xy)^2$, to get:

$\displaystyle dx+\left[ y^2(1-xy)^2+x^2 \right]dy=0$

Here, I tried the substitution $\displaystyle t=xy$. But it does not work, doesn't it?

Any help is appreciated .