\[
\boxed{
ax \left( {\frac {\rm d}{{\rm d}x}}y \left( x \right)  \right) ^{2}+ \left( bx-ay \left( x \right) +c \right) {\frac {\rm d}{{\rm d}x}}y \left( x \right) -by \left( x \right) =0}
\]