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