\[ y'(x)=\frac {\left (4 a x-y(x)^2\right )^3}{y(x) \left (4 a x-y(x)^2-1\right )} \] ✓ Mathematica : cpu = 0.40781 (sec), leaf count = 89
\[\text {Solve}\left [2 a \left (x-\frac {\text {RootSum}\left [-\text {$\#$1}^3+2 \text {$\#$1} a-2 a\& ,\frac {\text {$\#$1} a \log \left (-\text {$\#$1}+4 a x-y(x)^2\right )-a \log \left (-\text {$\#$1}+4 a x-y(x)^2\right )}{2 a-3 \text {$\#$1}^2}\& \right ]}{2 a}\right )=c_1,y(x)\right ]\] ✗ Maple : cpu = 0. (sec), leaf count = 0 , could not solve
dsolve(diff(y(x),x) = (4*a*x-y(x)^2)^3/(-y(x)^2+4*a*x-1)/y(x),y(x))