\[
\boxed{
{x}^{2} \left( 2-9\,x \right)  \left( {\frac {{\rm d}^{2}}{{\rm d}{x}^{2}}}y \left( x \right)  \right) ^{2}-6\,x \left( 1-6\,x \right)  \left( {\frac {\rm d}{{\rm d}x}}y \left( x \right)  \right) {\frac {{\rm d}^{2}}{{\rm d}{x}^{2}}}y \left( x \right) +6\, \left( {\frac {{\rm d}^{2}}{{\rm d}{x}^{2}}}y \left( x \right)  \right) y \left( x \right) -36\,x \left( {\frac {\rm d}{{\rm d}x}}y \left( x \right)  \right) ^{2}=0}
\]