\[ y'(x)=\frac {F\left (x^2+y(x)^2\right )-x}{y(x)} \] ✓ Mathematica : cpu = 0.164708 (sec), leaf count = 95
DSolve[Derivative[1][y][x] == (-x + F[x^2 + y[x]^2])/y[x],y[x],x]
\[\text {Solve}\left [\int _1^{y(x)}\left (-\frac {K[2]}{F\left (x^2+K[2]^2\right )}-\int _1^x\frac {2 K[1] K[2] F'\left (K[1]^2+K[2]^2\right )}{F\left (K[1]^2+K[2]^2\right )^2}dK[1]\right )dK[2]+\int _1^x\left (1-\frac {K[1]}{F\left (K[1]^2+y(x)^2\right )}\right )dK[1]=c_1,y(x)\right ]\] ✓ Maple : cpu = 0.106 (sec), leaf count = 57
dsolve(diff(y(x),x) = (-x+F(y(x)^2+x^2))/y(x),y(x))
\[y \left (x \right ) = \sqrt {-x^{2}+\RootOf \left (-2 x +\int _{}^{\textit {\_Z}}\frac {1}{F \left (\textit {\_a} \right )}d \textit {\_a} +2 c_{1}\right )}\]