\[
\boxed{
a{x}^{2}{\frac {{\rm d}^{2}}{{\rm d}{x}^{2}}}y \left( x \right) +bx{\frac {\rm d}{{\rm d}x}}y \left( x \right) + \left( c{x}^{2}+dx+f \right) y \left( x \right) =0}
\]