\[ a y(x)+(b+x) y'(x)+x y''(x)=0 \] ✓ Mathematica : cpu = 0.0347494 (sec), leaf count = 40
\[\left \{\left \{y(x)\to c_1 e^{-x} U(b-a,b,x)+c_2 e^{-x} L_{a-b}^{b-1}(x)\right \}\right \}\]
✓ Maple : cpu = 0.082 (sec), leaf count = 33
\[ \left \{ y \left ( x \right ) ={\it \_C1}\,{{\rm e}^{-x}}{{\sl M}\left (-a+b,\,b,\,x\right )}+{\it \_C2}\,{{\rm e}^{-x}}{{\sl U}\left (-a+b,\,b,\,x\right )} \right \} \]