\[ 3 x^2 y'(x)-x^2-3 x y(x)-7 y(x)^2=0 \] ✓ Mathematica : cpu = 0.0231798 (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 = 0.028 (sec), leaf count = 20
\[ \left \{ y \left ( x \right ) ={\frac {x\sqrt {7}}{7}\tan \left ( {\frac { \left ( \ln \left ( x \right ) +{\it \_C1} \right ) \sqrt {7}}{3}} \right ) } \right \} \]