\[ a+x y'(x)^3-y(x) y'(x)^2=0 \] ✓ Mathematica : cpu = 0.0041365 (sec), leaf count = 16
\[\left \{\left \{y(x)\to \frac {a}{c_1{}^2}+c_1 x\right \}\right \}\] ✓ Maple : cpu = 0.04 (sec), leaf count = 76
\[y \relax (x ) = \frac {3 \,2^{\frac {1}{3}} \left (a \,x^{2}\right )^{\frac {1}{3}}}{2}\]