\[ y''(x)=\frac {2 (a x+2 b) y'(x)}{x (a x+b)}-\frac {y(x) (2 a x+6 b)}{x^2 (a x+b)} \] ✓ Mathematica : cpu = 0.040887 (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 = 0.032 (sec), leaf count = 29
\[ \left \{ y \left ( x \right ) ={\frac {{\it \_C1}\,{x}^{2}}{ax+b}}+{\frac {{\it \_C2}\,{x}^{3}}{ax+b}} \right \} \]