\[ \boxed { {\frac {\rm d}{{\rm d}x}}y \left ( x \right ) +f \left ( x \right ) \left ( y \left ( x \right ) \right ) ^{2}+g \left ( x \right ) y \left ( x \right ) =0} \]
Mathematica: cpu = 0.507064 (sec), leaf count = 51 \[ \left \{\left \{y(x)\to \frac {e^{\int _1^x -g(K[1]) \, dK[1]}}{c_1-\int _1^x f(K[2]) \left (-e^{\int _1^{K[2]} -g(K[1]) \, dK[1]}\right ) \, dK[2]}\right \}\right \} \]
Maple: cpu = 0.031 (sec), leaf count = 28 \[ \left \{ y \left ( x \right ) ={\frac {{{\rm e}^{\int \!-g \left ( x \right ) \,{\rm d}x}}}{\int \!{{\rm e}^{\int \!-g \left ( x \right ) \,{\rm d}x}}f \left ( x \right ) \,{\rm d}x+{\it \_C1}}} \right \} \]
Sage: cpu = 0.112 (sec), leaf count = 0 \[ \left [\frac {e^{\left (-\int g\left (x\right )\,{d x}\right )}}{c + \int e^{\left (-\int g\left (x\right )\,{d x}\right )} f\left (x\right )\,{d x}}, \text {\texttt {bernoulli}}\right ] \]