\[ \boxed { \left ( x\sin \left ( xy \left ( x \right ) \right ) +\cos \left ( y \left ( x \right ) +x \right ) -\sin \left ( y \left ( x \right ) \right ) \right ) {\frac {\rm d}{{\rm d}x}}y \left ( x \right ) +y \left ( x \right ) \sin \left ( xy \left ( x \right ) \right ) +\cos \left ( y \left ( x \right ) +x \right ) +\cos \left ( x \right ) =0} \]
Mathematica: cpu = 0.213027 (sec), leaf count = 31 \[ \text {Solve}\left [\cos (y(x))-\cos (x y(x))+\sin (x) \cos (y(x))+\cos (x) \sin (y(x))+\sin (x)=c_1,y(x)\right ] \]
Maple: cpu = 0.172 (sec), leaf count = 22 \[ \left \{ -\cos \left ( xy \left ( x \right ) \right ) +\sin \left ( y \left ( x \right ) +x \right ) +\sin \left ( x \right ) +\cos \left ( y \left ( x \right ) \right ) +{\it \_C1}=0 \right \} \]