\[ y'(x)=\frac {x^2 \left (\sqrt {4 y(x)^3-9 x^4}+3 x\right )}{y(x)^2} \] ✗ Mathematica : cpu = 300.059 (sec), leaf count = 0 , timed out
$Aborted
✓ Maple : cpu = 0.202 (sec), leaf count = 36
\[ \left \{ \int _{{\it \_b}}^{y \left ( x \right ) }\!{{{\it \_a}}^{2}{\frac {1}{\sqrt {-9\,{x}^{4}+4\,{{\it \_a}}^{3}}}}}\,{\rm d}{\it \_a}-{\frac {{x}^{3}}{3}}-{\it \_C1}=0 \right \} \]