\[ x y'(x)-\sin (x-y(x))=0 \] ✗ Mathematica : cpu = 1.91185 (sec), leaf count = 0 , could not solve
DSolve[-Sin[x - y[x]] + x*Derivative[1][y][x] == 0, y[x], x]
✗ Maple : cpu = 0. (sec), leaf count = 0 , could not solve
dsolve(x*diff(y(x),x)-sin(x-y(x)) = 0,y(x))