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