\[ y'(x)=\frac {F((y(x)-x) (y(x)+x))+x}{y(x)} \] ✓ Mathematica : cpu = 0.234941 (sec), leaf count = 109
\[\text {Solve}\left [\int _1^{y(x)}\left (-\frac {K[2]}{F((K[2]-x) (x+K[2]))}-\int _1^x-\frac {2 K[1] K[2] F'((K[2]-K[1]) (K[1]+K[2]))}{F((K[2]-K[1]) (K[1]+K[2]))^2}dK[1]\right )dK[2]+\int _1^x\left (\frac {K[1]}{F((y(x)-K[1]) (K[1]+y(x)))}+1\right )dK[1]=c_1,y(x)\right ]\] ✓ Maple : cpu = 0.121 (sec), leaf count = 53
\[\left \{y \left (x \right ) = \sqrt {x^{2}+\RootOf \left (2 c_{1}-2 x +\int _{}^{\textit {\_Z}}\frac {1}{F \left (\textit {\_a} \right )}d \textit {\_a} \right )}, y \left (x \right ) = -\sqrt {x^{2}+\RootOf \left (2 c_{1}-2 x +\int _{}^{\textit {\_Z}}\frac {1}{F \left (\textit {\_a} \right )}d \textit {\_a} \right )}\right \}\]