\[ \boxed { {x}^{2} \left ( {\frac {\rm d}{{\rm d}x}}y \left ( x \right ) + \left ( y \left ( x \right ) \right ) ^{2} \right ) +axy \left ( x \right ) +b=0} \]
Mathematica: cpu = 0.026003 (sec), leaf count = 67 \[ \left \{\left \{y(x)\to -\frac {\sqrt {a^2-2 a-4 b+1} \left (\frac {2 c_1}{x^{\sqrt {a^2-2 a-4 b+1}}+c_1}-1\right )-1}{2 x}-\frac {a}{2 x}\right \}\right \} \]
Maple: cpu = 0.031 (sec), leaf count = 64 \[ \left \{ y \left ( x \right ) ={\frac {1}{2\,x} \left ( -\tanh \left ( -{ \frac {\ln \left ( x \right ) }{2}\sqrt {{a}^{2}-2\,a-4\,b+1}}+{\frac { {\it \_C1}}{2}\sqrt {{a}^{2}-2\,a-4\,b+1}} \right ) \sqrt {{a}^{2}-2\,a -4\,b+1}-a+1 \right ) } \right \} \]