\[ y'(x)=\frac {e^{b x}}{e^{-b x} y(x)+1} \] ✓ Mathematica : cpu = 0.349992 (sec), leaf count = 101
\[\text {Solve}\left [\frac {1}{2} b \left (\log \left (-b e^{-2 b x} y(x)^2-b e^{-b x} y(x)+1\right )+2 b x\right )=\frac {b \tan ^{-1}\left (\frac {(b+2) \left (-e^{b x}\right )-b y(x)}{b \sqrt {-\frac {b+4}{b}} \left (e^{b x}+y(x)\right )}\right )}{\sqrt {-\frac {b+4}{b}}}+c_1,y(x)\right ]\] ✓ Maple : cpu = 1.156 (sec), leaf count = 98
\[ \left \{ y \left ( x \right ) ={\frac {1}{{{\rm e}^{-bx}}}{\it RootOf} \left ( -{{\rm e}^{{\it RootOf} \left ( \left ( \tanh \left ( {\frac {2\,{\it \_C1}\,b-2\,bx-{\it \_Z}}{2\,b}\sqrt {{b}^{2}+4\,b}} \right ) \right ) ^{2}b+4\, \left ( \tanh \left ( 1/2\,{\frac {\sqrt {{b}^{2}+4\,b} \left ( 2\,{\it \_C1}\,b-2\,bx-{\it \_Z} \right ) }{b}} \right ) \right ) ^{2}-4\,{{\rm e}^{{\it \_Z}}}-b-4 \right ) }}-1+{\it \_Z}\,b+b{{\it \_Z}}^{2} \right ) } \right \} \]