\[ y'(x) (-\sin (y(x))+x \sin (x y(x))+\cos (y(x)+x))+y(x) \sin (x y(x))+\cos (y(x)+x)+\cos (x)=0 \] ✓ Mathematica : cpu = 0.3685 (sec), leaf count = 23
\[\text {Solve}\left [c_1+\cos (x y(x))=\sin (y(x)+x)+\cos (y(x))+\sin (x),y(x)\right ]\]
✓ Maple : cpu = 0.249 (sec), leaf count = 22
\[ \left \{ -\cos \left ( xy \left ( x \right ) \right ) +\sin \left ( x \right ) +\sin \left ( y \left ( x \right ) +x \right ) +\cos \left ( y \left ( x \right ) \right ) +{\it \_C1}=0 \right \} \]