\[ \boxed { \left ( x{\frac {\rm d}{{\rm d}x}}y \left ( x \right ) -y \left ( x \right ) \right ) \left ( \cos \left ( {\frac {y \left ( x \right ) }{x}} \right ) \right ) ^{2}+x=0} \]
Mathematica: cpu = 0.035005 (sec), leaf count = 33 \[ \text {Solve}\left [\frac {y(x)}{2 x}+\frac {1}{4} \sin \left (\frac {2 y(x)}{x}\right )=c_1-\log (x),y(x)\right ] \]
Maple: cpu = 0.062 (sec), leaf count = 35 \[ \left \{ -{\frac {1}{2\,x} \left ( \cos \left ( {\frac {y \left ( x \right ) }{x}} \right ) \sin \left ( {\frac {y \left ( x \right ) }{x}} \right ) x+y \left ( x \right ) \right ) }-\ln \left ( x \right ) -{\it \_C1}=0 \right \} \]