\[ y'(x)+\sin \left (y'(x)\right )-x=0 \] ✗ Mathematica : cpu = 0.0110075 (sec), leaf count = 0 , could not solve
DSolve[-x + Sin[Derivative[1][y][x]] + Derivative[1][y][x] == 0, y[x], x]
✓ Maple : cpu = 0.032 (sec), leaf count = 16
\[ \left \{ y \left ( x \right ) =\int \!{\it RootOf} \left ( {\it \_Z}+\sin \left ( {\it \_Z} \right ) -x \right ) \,{\rm d}x+{\it \_C1} \right \} \]