\[ 3 x^2 y'(x)-x^2-3 x y(x)-7 y(x)^2=0 \] ✓ Mathematica : cpu = 0.0927967 (sec), leaf count = 35
DSolve[-x^2 - 3*x*y[x] - 7*y[x]^2 + 3*x^2*Derivative[1][y][x] == 0,y[x],x]
\[\left \{\left \{y(x)\to \frac {x \tan \left (\frac {1}{3} \left (\sqrt {7} \log (x)+3 \sqrt {7} c_1\right )\right )}{\sqrt {7}}\right \}\right \}\] ✓ Maple : cpu = 0.034 (sec), leaf count = 20
dsolve(3*x^2*diff(y(x),x)-7*y(x)^2-3*x*y(x)-x^2 = 0,y(x))
\[y \left (x \right ) = \frac {\tan \left (\frac {\left (\ln \left (x \right )+c_{1}\right ) \sqrt {7}}{3}\right ) x \sqrt {7}}{7}\]