\[
\boxed{
 \left( 6\,x \left( y \left( x \right)  \right) ^{2}+{x}^{2} \right) {\frac {\rm d}{{\rm d}x}}y \left( x \right) -y \left( x \right)  \left( 3\, \left( y \left( x \right)  \right) ^{2}-x \right) =0}
\]