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