\[
\boxed{
x \left( x-1 \right) {\frac {{\rm d}^{2}}{{\rm d}{x}^{2}}}y \left( x \right) + \left(  \left( {\it a1}+{\it b1}+1 \right) x-{\it d1} \right) {\frac {\rm d}{{\rm d}x}}y \left( x \right) +{\it a1}\,{\it b1}\,{\it d1}=0}
\]