\[ \boxed { x \left ( {\frac {\rm d}{{\rm d}x}}y \left ( x \right ) \right ) ^{2}+ \left ( y \left ( x \right ) -3\,x \right ) {\frac {\rm d}{{\rm d}x}}y \left ( x \right ) +y \left ( x \right ) =0} \]
Mathematica: cpu = 0 (sec), leaf count = 0 \[ \text {Hanged} \]
Maple: cpu = 0.546 (sec), leaf count = 136 \[ \left \{ -{\frac {{\it \_C1}}{x} \left ( 5\,x-y \left ( x \right ) + \sqrt {9\,{x}^{2}-10\,xy \left ( x \right ) + \left ( y \left ( x \right ) \right ) ^{2}} \right ) \left ( {\frac {1}{x} \left ( 3\,x-y \left ( x \right ) +\sqrt {9\,{x}^{2}-10\,xy \left ( x \right ) + \left ( y \left ( x \right ) \right ) ^{2}} \right ) } \right ) ^{-{\frac {3}{2}}}}+x=0,{ \frac {{\it \_C1}}{x} \left ( -5\,x+y \left ( x \right ) +\sqrt {9\,{x}^{ 2}-10\,xy \left ( x \right ) + \left ( y \left ( x \right ) \right ) ^{2}} \right ) \left ( {\frac {1}{x} \left ( 6\,x-2\,y \left ( x \right ) -2\, \sqrt {9\,{x}^{2}-10\,xy \left ( x \right ) + \left ( y \left ( x \right ) \right ) ^{2}} \right ) } \right ) ^{-{\frac {3}{2}}}}+x=0,y \left ( x \right ) =x \right \} \]