\[ y'(x)=e^{b x} \left (e^{-3 b x} y(x)^3+e^{-2 b x} y(x)^2+1\right ) \] ✓ Mathematica : cpu = 0.370088 (sec), leaf count = 146
DSolve[Derivative[1][y][x] == E^(b*x)*(1 + y[x]^2/E^(2*b*x) + y[x]^3/E^(3*b*x)),y[x],x]
\[\text {Solve}\left [-\frac {1}{3} (9 b+29)^{2/3} \text {RootSum}\left [\text {$\#$1}^3 (9 b+29)^{2/3}-9 \text {$\#$1} b-3 \text {$\#$1}+(9 b+29)^{2/3}\& ,\frac {\log \left (\frac {3 e^{-2 b x} y(x)+e^{-b x}}{\sqrt [3]{(9 b+29) e^{-3 b x}}}-\text {$\#$1}\right )}{\text {$\#$1}^2 \left (-(9 b+29)^{2/3}\right )+3 b+1}\& \right ]=\frac {1}{9} x e^{2 b x} \left ((9 b+29) e^{-3 b x}\right )^{2/3}+c_1,y(x)\right ]\] ✓ Maple : cpu = 0.111 (sec), leaf count = 40
dsolve(diff(y(x),x) = (1+y(x)^2*exp(-2*b*x)+y(x)^3*exp(-3*b*x))*exp(b*x),y(x))
\[y \left (x \right ) = \RootOf \left (-x -\left (\int _{}^{\textit {\_Z}}-\frac {1}{\textit {\_a}^{3}+\textit {\_a}^{2}-\textit {\_a} b +1}d \textit {\_a} \right )+c_{1}\right ) {\mathrm e}^{b x}\]