\[ y'(x)=\frac {1}{3} x \left (3 \sqrt {x^2+3 y(x)}-2\right ) \] ✓ Mathematica : cpu = 0.0882638 (sec), leaf count = 33
\[\left \{\left \{y(x)\to \frac {1}{48} \left (-54 c_1 x^2+81 c_1^2+9 x^4-16 x^2\right )\right \}\right \}\] ✓ Maple : cpu = 0.339 (sec), leaf count = 23
\[ \left \{ {\it \_C1}+{\frac {3\,{x}^{2}}{4}}+{\frac {2}{3}}-\sqrt {{x}^{2}+3\,y \left ( x \right ) }=0 \right \} \]