\[ \boxed { 3\,{x}^{2}{\frac {\rm d}{{\rm d}x}}y \left ( x \right ) -7\, \left ( y \left ( x \right ) \right ) ^{2}-3\,xy \left ( x \right ) -{x}^{2}=0} \]
Mathematica: cpu = 0.022003 (sec), leaf count = 35 \[ \left \{\left \{y(x)\to \frac {x \tan \left (\frac {1}{3} \left (3 \sqrt {7} c_1+\sqrt {7} \log (x)\right )\right )}{\sqrt {7}}\right \}\right \} \]
Maple: cpu = 0.031 (sec), leaf count = 20 \[ \left \{ y \left ( x \right ) ={\frac {x\sqrt {7}}{7}\tan \left ( {\frac { \left ( \ln \left ( x \right ) +{\it \_C1} \right ) \sqrt {7}}{3}} \right ) } \right \} \]