\[ x^3 y''(x)-a \left (x y'(x)-y(x)\right )^2=0 \] ✓ Mathematica : cpu = 0.0782767 (sec), leaf count = 25
\[\left \{\left \{y(x)\to -\frac {x \log \left (-\frac {a \left (c_2 x+c_1\right )}{x}\right )}{a}\right \}\right \}\]
✓ Maple : cpu = 0.056 (sec), leaf count = 23
\[ \left \{ y \left ( x \right ) =-{\frac {x}{a}\ln \left ( {\frac {a \left ( {\it \_C1}\,x-{\it \_C2} \right ) }{x}} \right ) } \right \} \]