\[ \left (x y'(x)-y(x)\right ) \left (a x^2+b x+c\right )+x^2-y(x)^2=0 \] ✓ Mathematica : cpu = 0.372908 (sec), leaf count = 132
\[\left \{\left \{y(x)\to -\frac {x \left (-1+\exp \left (\frac {4 \tan ^{-1}\left (\frac {2 a x}{\sqrt {4 a c-b^2}}+\frac {b}{\sqrt {4 a c-b^2}}\right )}{\sqrt {4 a c-b^2}}+2 c_1\right )\right )}{1+\exp \left (\frac {4 \tan ^{-1}\left (\frac {2 a x}{\sqrt {4 a c-b^2}}+\frac {b}{\sqrt {4 a c-b^2}}\right )}{\sqrt {4 a c-b^2}}+2 c_1\right )}\right \}\right \}\] ✓ Maple : cpu = 0.064 (sec), leaf count = 58
\[y \relax (x ) = -\tanh \left (\frac {c_{1} \sqrt {4 a c -b^{2}}+2 \arctan \left (\frac {2 a x +b}{\sqrt {4 a c -b^{2}}}\right )}{\sqrt {4 a c -b^{2}}}\right ) x\]