\[
\boxed{
{\frac {\rm d}{{\rm d}x}}y \left( x \right) ={\frac {-4\,axy \left( x \right) -{a}^{2}{x}^{3}-2\,a{x}^{2}b-4\,ax+8}{8\,y \left( x \right) +2\,a{x}^{2}+4\,bx+8}}=0}
\]