\[ y'(x)=x^2 \sqrt {x^2+3 y(x)}+\sqrt {x^2+3 y(x)}+x^3 \sqrt {x^2+3 y(x)}-\frac {2 x}{3} \] ✓ Mathematica : cpu = 0.266226 (sec), leaf count = 63
\[\left \{\left \{y(x)\to \frac {1}{192} \left (\left (96-72 c_1\right ) x^4-96 c_1 x^3-288 c_1 x+144 c_1^2+9 x^8+24 x^7+16 x^6+72 x^5+80 x^2\right )\right \}\right \}\]
✓ Maple : cpu = 0.25 (sec), leaf count = 30
\[ \left \{ {\it \_C1}+{\frac {3\,{x}^{4}}{8}}+{\frac {{x}^{3}}{2}}+{\frac {3\,x}{2}}-\sqrt {{x}^{2}+3\,y \left ( x \right ) }=0 \right \} \]