\[ y'(x)=\frac {\sqrt {y(x)}}{F\left (\frac {x-y(x)}{\sqrt {y(x)}}\right )+\sqrt {y(x)}} \] ✓ Mathematica : cpu = 0.452795 (sec), leaf count = 274
DSolve[Derivative[1][y][x] == Sqrt[y[x]]/(F[(x - y[x])/Sqrt[y[x]]] + Sqrt[y[x]]),y[x],x]
\[\text {Solve}\left [\int _1^{y(x)}\left (-\frac {F\left (\frac {x-K[2]}{\sqrt {K[2]}}\right )}{x \sqrt {K[2]}}-\int _1^x-\frac {-\frac {F\left (\frac {K[1]-K[2]}{\sqrt {K[2]}}\right )}{\sqrt {K[2]}}-2 \left (-\frac {K[1]-K[2]}{2 K[2]^{3/2}}-\frac {1}{\sqrt {K[2]}}\right ) \sqrt {K[2]} F'\left (\frac {K[1]-K[2]}{\sqrt {K[2]}}\right )-1}{\left (-2 \sqrt {K[2]} F\left (\frac {K[1]-K[2]}{\sqrt {K[2]}}\right )+K[1]-K[2]\right )^2}dK[1]+\frac {2 F\left (\frac {x-K[2]}{\sqrt {K[2]}}\right )^2+\sqrt {K[2]} F\left (\frac {x-K[2]}{\sqrt {K[2]}}\right )+x}{x \left (-x+K[2]+2 F\left (\frac {x-K[2]}{\sqrt {K[2]}}\right ) \sqrt {K[2]}\right )}\right )dK[2]+\int _1^x\frac {1}{-2 \sqrt {y(x)} F\left (\frac {K[1]-y(x)}{\sqrt {y(x)}}\right )+K[1]-y(x)}dK[1]=c_1,y(x)\right ]\] ✓ Maple : cpu = 0.17 (sec), leaf count = 40
dsolve(diff(y(x),x) = y(x)^(1/2)/(y(x)^(1/2)+F((x-y(x))/y(x)^(1/2))),y(x))
\[\frac {\ln \left (y \left (x \right )\right )}{2}-\left (\int _{}^{\frac {x}{\sqrt {y \left (x \right )}}-\sqrt {y \left (x \right )}}\frac {1}{2 F \left (\textit {\_a} \right )-\textit {\_a}}d \textit {\_a} \right )-c_{1} = 0\]