\[ y'(x) (-\sin (y(x))+x \sin (x y(x))+\cos (y(x)+x))+y(x) \sin (x y(x))+\cos (y(x)+x)+\cos (x)=0 \] ✓ Mathematica : cpu = 0.850341 (sec), leaf count = 31
DSolve[Cos[x] + Cos[x + y[x]] + Sin[x*y[x]]*y[x] + (Cos[x + y[x]] - Sin[y[x]] + x*Sin[x*y[x]])*Derivative[1][y][x] == 0,y[x],x]
\[\text {Solve}[\cos (y(x))-\cos (x y(x))+\sin (x) \cos (y(x))+\cos (x) \sin (y(x))+\sin (x)=c_1,y(x)]\] ✓ Maple : cpu = 0.234 (sec), leaf count = 22
dsolve((x*sin(x*y(x))+cos(y(x)+x)-sin(y(x)))*diff(y(x),x)+y(x)*sin(x*y(x))+cos(y(x)+x)+cos(x) = 0,y(x))
\[-\cos \left (x y \left (x \right )\right )+\sin \left (x \right )+\sin \left (y \left (x \right )+x \right )+\cos \left (y \left (x \right )\right )+c_{1} = 0\]