\[ y''(x)=\frac {2 (a x+2 b) y'(x)}{x (a x+b)}-\frac {y(x) (2 a x+6 b)}{x^2 (a x+b)} \] ✓ Mathematica : cpu = 0.0273789 (sec), leaf count = 32
\[\left \{\left \{y(x)\to \frac {c_2 x^3}{a x+b}+\frac {c_1 x^2}{a x+b}\right \}\right \}\] ✓ Maple : cpu = 0.049 (sec), leaf count = 20
\[ \left \{ y \left ( x \right ) ={\frac {{x}^{2} \left ( {\it \_C2}\,x+{\it \_C1} \right ) }{ax+b}} \right \} \]