\[ \boxed { 2\, \left ( {\frac {{\rm d}^{2}}{{\rm d}{x}^{2}}}y \left ( x \right ) \right ) y \left ( x \right ) - \left ( {\frac {\rm d}{{\rm d}x}}y \left ( x \right ) \right ) ^{2}+ \left ( ay \left ( x \right ) +b \right ) \left ( y \left ( x \right ) \right ) ^{2}=0} \]
Mathematica: cpu = 2.552324 (sec), leaf count = 437 \[ \left \{\left \{y(x)\to \text {InverseFunction}\left [-\frac {i \sqrt {2} \text {$\#$1}^{3/2} \sqrt {\frac {4 c_1}{\text {$\#$1} \left (\sqrt {2 a c_1+b^2}-b\right )}+2} \sqrt {1-\frac {2 c_1}{\text {$\#$1} \left (\sqrt {2 a c_1+b^2}+b\right )}} F\left (i \sinh ^{-1}\left (\frac {\sqrt {2} \sqrt {\frac {c_1}{\sqrt {b^2+2 a c_1}-b}}}{\sqrt {\text {$\#$1}}}\right )|\frac {b-\sqrt {b^2+2 a c_1}}{b+\sqrt {b^2+2 a c_1}}\right )}{\sqrt {\frac {c_1}{\sqrt {2 a c_1+b^2}-b}} \sqrt {-\text {$\#$1} \left (\text {$\#$1}^2 a+2 \text {$\#$1} b-2 c_1\right )}}\& \right ]\left [c_2+x\right ]\right \},\left \{y(x)\to \text {InverseFunction}\left [\frac {i \sqrt {2} \text {$\#$1}^{3/2} \sqrt {\frac {4 c_1}{\text {$\#$1} \left (\sqrt {2 a c_1+b^2}-b\right )}+2} \sqrt {1-\frac {2 c_1}{\text {$\#$1} \left (\sqrt {2 a c_1+b^2}+b\right )}} F\left (i \sinh ^{-1}\left (\frac {\sqrt {2} \sqrt {\frac {c_1}{\sqrt {b^2+2 a c_1}-b}}}{\sqrt {\text {$\#$1}}}\right )|\frac {b-\sqrt {b^2+2 a c_1}}{b+\sqrt {b^2+2 a c_1}}\right )}{\sqrt {\frac {c_1}{\sqrt {2 a c_1+b^2}-b}} \sqrt {-\text {$\#$1} \left (\text {$\#$1}^2 a+2 \text {$\#$1} b-2 c_1\right )}}\& \right ]\left [c_2+x\right ]\right \}\right \} \]
Maple: cpu = 1.560 (sec), leaf count = 71 \[ \left \{ \int ^{y \left ( x \right ) }\!-2\,{\frac {1}{\sqrt {-2\,a{{ \it \_a}}^{3}-4\,b{{\it \_a}}^{2}+4\,{\it \_a}\,{\it \_C1}}}}{d{\it \_a}}-x-{\it \_C2}=0,\int ^{y \left ( x \right ) }\!2\,{\frac {1}{\sqrt {-2\,a{{\it \_a}}^{3}-4\,b{{\it \_a}}^{2}+4\,{\it \_a}\,{\it \_C1}}}}{ d{\it \_a}}-x-{\it \_C2}=0 \right \} \]