\[ y'(x)=-\frac {2 a}{128 a^4 x^3-96 a^3 x^2 y(x)^2-32 a^3 x^2+24 a^2 x y(x)^4+16 a^2 x y(x)^2-2 a y(x)^6-2 a y(x)^4-2 a-y(x)} \] ✓ Mathematica : cpu = 0.171101 (sec), leaf count = 10
\[\left \{\left \{y(x)\to 2 a c_1\right \}\right \}\]
✓ Maple : cpu = 0.07 (sec), leaf count = 41
\[ \left \{ {\frac {y \left ( x \right ) }{2\,a}}+{\frac {\int ^{ \left ( y \left ( x \right ) \right ) ^{2}-4\,ax}\! \left ( {{\it \_a}}^{3}+{{\it \_a}}^{2}+1 \right ) ^{-1}{d{\it \_a}}}{8\,{a}^{2}}}-{\it \_C1}=0 \right \} \]