\[ (x-y(x)) y''(x)+\left (-y'(x)-1\right ) \left (y'(x)^2+1\right )=0 \] ✓ Mathematica : cpu = 1.69358 (sec), leaf count = 75
DSolve[(-1 - Derivative[1][y][x])*(1 + Derivative[1][y][x]^2) + (x - y[x])*Derivative[2][y][x] == 0,y[x],x]
\[\left \{\left \{y(x)\to -\sqrt {-x^2-2 c_2 x+e^{2 c_1}-c_2{}^2}-c_2\right \},\left \{y(x)\to \sqrt {-x^2-2 c_2 x+e^{2 c_1}-c_2{}^2}-c_2\right \}\right \}\] ✓ Maple : cpu = 1.332 (sec), leaf count = 105
dsolve(diff(diff(y(x),x),x)*(x-y(x))-(diff(y(x),x)+1)*(diff(y(x),x)^2+1)=0,y(x))
\[y \left (x \right ) = x +\RootOf \left (-x +\int _{}^{\textit {\_Z}}-\frac {c_{1}^{2} \textit {\_f}^{2}-1}{c_{1}^{2} \textit {\_f}^{2}+c_{1} \sqrt {-c_{1}^{2} \textit {\_f}^{2}+2}\, \textit {\_f} -2}d \textit {\_f} +c_{2}\right )\]