\[ y'(x)=\frac {2 a \left (-4 a+x y(x)^2+x\right )}{-128 a^4+96 a^3 x y(x)^2-24 a^2 x^2 y(x)^4+2 a x^3 y(x)^6+4 a x^2 y(x)-x^3 y(x)^3-x^3 y(x)} \] ✓ Mathematica : cpu = 2.05103 (sec), leaf count = 401
\[\left \{\left \{y(x)\to \text {Root}\left [8 \text {$\#$1}^5 a x^2-8 \text {$\#$1}^4 a c_1 x^2-64 \text {$\#$1}^3 a^2 x+\text {$\#$1}^2 \left (64 a^2 c_1 x+2 x^2\right )+128 \text {$\#$1} a^3-128 a^3 c_1-8 a x+x^2\& ,1\right ]\right \},\left \{y(x)\to \text {Root}\left [8 \text {$\#$1}^5 a x^2-8 \text {$\#$1}^4 a c_1 x^2-64 \text {$\#$1}^3 a^2 x+\text {$\#$1}^2 \left (64 a^2 c_1 x+2 x^2\right )+128 \text {$\#$1} a^3-128 a^3 c_1-8 a x+x^2\& ,2\right ]\right \},\left \{y(x)\to \text {Root}\left [8 \text {$\#$1}^5 a x^2-8 \text {$\#$1}^4 a c_1 x^2-64 \text {$\#$1}^3 a^2 x+\text {$\#$1}^2 \left (64 a^2 c_1 x+2 x^2\right )+128 \text {$\#$1} a^3-128 a^3 c_1-8 a x+x^2\& ,3\right ]\right \},\left \{y(x)\to \text {Root}\left [8 \text {$\#$1}^5 a x^2-8 \text {$\#$1}^4 a c_1 x^2-64 \text {$\#$1}^3 a^2 x+\text {$\#$1}^2 \left (64 a^2 c_1 x+2 x^2\right )+128 \text {$\#$1} a^3-128 a^3 c_1-8 a x+x^2\& ,4\right ]\right \},\left \{y(x)\to \text {Root}\left [8 \text {$\#$1}^5 a x^2-8 \text {$\#$1}^4 a c_1 x^2-64 \text {$\#$1}^3 a^2 x+\text {$\#$1}^2 \left (64 a^2 c_1 x+2 x^2\right )+128 \text {$\#$1} a^3-128 a^3 c_1-8 a x+x^2\& ,5\right ]\right \}\right \}\]
✓ Maple : cpu = 3.152 (sec), leaf count = 71
\[ \left \{ {\frac {x \left ( y \left ( x \right ) \right ) ^{4}+ \left ( -4\,a+x \right ) \left ( y \left ( x \right ) \right ) ^{2}-2\,a}{2\,a \left ( y \left ( x \right ) \right ) ^{4} \left ( -x \left ( y \left ( x \right ) \right ) ^{2}+4\,a \right ) ^{2}}}+{\frac {8\,a \left ( y \left ( x \right ) \right ) ^{5}+2\, \left ( y \left ( x \right ) \right ) ^{2}+1}{16\,{a}^{2} \left ( y \left ( x \right ) \right ) ^{4}}}+{\it \_C1}=0 \right \} \]