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