\[ \boxed { {\frac {\rm d}{{\rm d}x}}y \left ( x \right ) = \left ( y \left ( x \right ) \right ) ^{3}+{x}^{2} \left ( y \left ( x \right ) \right ) ^{2}+1/3\,y \left ( x \right ) {x}^{4}+1/27\,{x}^{6}-2/3\,x=0} \]
Mathematica: cpu = 0.011501 (sec), leaf count = 47 \[ \left \{\left \{y(x)\to -\frac {1}{\sqrt {c_1-2 x}}-\frac {x^2}{3}\right \},\left \{y(x)\to \frac {1}{\sqrt {c_1-2 x}}-\frac {x^2}{3}\right \}\right \} \]
Maple: cpu = 0.032 (sec), leaf count = 59 \[ \left \{ y \left ( x \right ) =-{\frac {1}{3} \left ( {x}^{2}\sqrt {-54\, {\it \_C1}-2\,x}-3 \right ) {\frac {1}{\sqrt {-54\,{\it \_C1}-2\,x}}}}, y \left ( x \right ) =-{\frac {1}{3} \left ( {x}^{2}\sqrt {-54\,{\it \_C1 }-2\,x}+3 \right ) {\frac {1}{\sqrt {-54\,{\it \_C1}-2\,x}}}} \right \} \]