y'(x)=-\frac{e^x \left(-8 y(x)^{9/2}+36 e^x y(x)^3-8 y(x)^3+24 e^x y(x)^{3/2}-54 e^{2 x} y(x)^{3/2}-18 e^{2 x}+27 e^{3 x}-8\right)}{8 \sqrt{y(x)}}