\[
\boxed{
{\frac {\rm d}{{\rm d}x}}y \left( x \right) ={\frac { \left( 3\,x \left( y \left( x \right)  \right) ^{2}+x+3\, \left( y \left( x \right)  \right) ^{2} \right) y \left( x \right) }{ \left( 6\, \left( y \left( x \right)  \right) ^{2}+x \right) x \left( 1+x \right) }}=0}
\]