\[ y''(x)=-\frac {c y(x)}{x^2 (a x+b)^2}-\frac {2 y'(x)}{x} \] ✓ Mathematica : cpu = 0.0341799 (sec), leaf count = 115
\[\left \{\left \{y(x)\to c_1 \exp \left (\frac {\sqrt {c} \left (-\frac {\sqrt {b^2-4 c}}{\sqrt {c}}-\frac {b}{\sqrt {c}}\right ) (\log (x)-\log (a x+b))}{2 b}\right )+c_2 \exp \left (\frac {\sqrt {c} \left (\frac {\sqrt {b^2-4 c}}{\sqrt {c}}-\frac {b}{\sqrt {c}}\right ) (\log (x)-\log (a x+b))}{2 b}\right )\right \}\right \}\] ✓ Maple : cpu = 0.263 (sec), leaf count = 79
\[ \left \{ y \left ( x \right ) =\sqrt {{\frac {ax+b}{x}}} \left ( \left ( {\frac {x}{ax+b}} \right ) ^{-{\frac {a}{2\,b}\sqrt {{\frac {{b}^{2}-4\,c}{{a}^{2}}}}}}{\it \_C2}+ \left ( {\frac {x}{ax+b}} \right ) ^{{\frac {a}{2\,b}\sqrt {{\frac {{b}^{2}-4\,c}{{a}^{2}}}}}}{\it \_C1} \right ) \right \} \]