\[
\boxed{
{\frac {\rm d}{{\rm d}x}}y \left( x \right) ={\frac {x \left( -x-1+{x}^{2}-2\,{x}^{2}y \left( x \right) +2\,{x}^{4} \right) }{ \left( {x}^{2}-y \left( x \right)  \right)  \left( 1+x \right) }}=0}
\]