\[ y'(x)=\frac {2 a}{x^2 \left (2 a F\left (\frac {x y(x)^2-4 a}{x}\right )-y(x)\right )} \] ✓ Mathematica : cpu = 0.383257 (sec), leaf count = 130
\[\text {Solve}\left [\int _1^{y(x)}\left (-\frac {K[2]}{2 a F\left (\frac {x K[2]^2-4 a}{x}\right )}-\int _1^x\frac {2 K[2] F'\left (\frac {K[1] K[2]^2-4 a}{K[1]}\right )}{F\left (\frac {K[1] K[2]^2-4 a}{K[1]}\right )^2 K[1]^2}dK[1]+1\right )dK[2]+\int _1^x-\frac {1}{F\left (\frac {K[1] y(x)^2-4 a}{K[1]}\right ) K[1]^2}dK[1]=c_1,y(x)\right ]\] ✓ Maple : cpu = 0.651 (sec), leaf count = 37
\[-\frac {y \relax (x )}{2 a}+\frac {\int _{}^{y \relax (x )^{2}-\frac {4 a}{x}}\frac {1}{F \left (\textit {\_a} \right )}d \textit {\_a}}{8 a^{2}}-c_{1} = 0\]