\[ y'(x)-(y(x)+x)^2=0 \] ✓ Mathematica : cpu = 0.0108231 (sec), leaf count = 30
\[\left \{\left \{y(x)\to \frac {1}{c_1 e^{2 i x}-\frac {i}{2}}-x-i\right \}\right \}\]
✓ Maple : cpu = 0.04 (sec), leaf count = 16
\[ \left \{ y \left ( x \right ) =-x-\tan \left ( -x+{\it \_C1} \right ) \right \} \]