\[
\boxed{
 \left( 2\,x \left( y \left( x \right)  \right) ^{3}-{x}^{4} \right) {\frac {\rm d}{{\rm d}x}}y \left( x \right) - \left( y \left( x \right)  \right) ^{4}+2\,{x}^{3}y \left( x \right) =0}
\]