\[
\boxed{
{\frac {{\rm d}^{2}}{{\rm d}{x}^{2}}}y \left( x \right) =12\,{\frac {y \left( x \right) }{ \left( 1+x \right) ^{2} \left( {x}^{2}+2\,x+3 \right) }}=0}
\]