\[ x y'(x)+y(x)^3+3 x y(x)^2=0 \] ✓ Mathematica : cpu = 0.464474 (sec), leaf count = 55
\[\text {Solve}\left [-3 x=\frac {2 e^{\frac {1}{2} \left (\frac {1}{y(x)}-3 x\right )^2}}{\sqrt {2 \pi } \text {erfi}\left (\frac {\frac {1}{y(x)}-3 x}{\sqrt {2}}\right )+2 c_1},y(x)\right ]\] ✓ Maple : cpu = 0.119 (sec), leaf count = 54
\[c_{1}-\frac {i {\mathrm e}^{\frac {\left (3 x y \relax (x )-1\right )^{2}}{2 y \relax (x )^{2}}}}{3 x}+\frac {\erf \left (\frac {\left (-i+3 i y \relax (x ) x \right ) \sqrt {2}}{2 y \relax (x )}\right ) \sqrt {2}\, \sqrt {\pi }}{2} = 0\]