\[ \boxed { \left ( {\frac {\rm d}{{\rm d}x}}y \left ( x \right ) \right ) ^{4}+3\, \left ( x-1 \right ) \left ( {\frac {\rm d}{{\rm d}x}}y \left ( x \right ) \right ) ^{2}-3\, \left ( 2\,y \left ( x \right ) -1 \right ) {\frac {\rm d}{{\rm d}x}}y \left ( x \right ) +3\,x=0} \]
Mathematica: cpu = 0 (sec), leaf count = 0 \[ \text {Hanged} \]
Maple: cpu = 0.125 (sec), leaf count = 245 \[ \left \{ y \left ( x \right ) =-x+{\frac {5}{6}},y \left ( x \right ) =x+{ \frac {1}{6}},y \left ( x \right ) ={\frac {x}{6} \left ( 3\, \left ( -{ \it \_C1}/2-1/2\,\sqrt {{{\it \_C1}}^{2}+4\,x} \right ) ^{2}+3 \right ) \left ( -{\frac {{\it \_C1}}{2}}-{\frac {1}{2}\sqrt {{{\it \_C1}}^{2}+ 4\,x}} \right ) ^{-1}}+{\frac {1}{6} \left ( \left ( -{\frac {{\it \_C1} }{2}}-{\frac {1}{2}\sqrt {{{\it \_C1}}^{2}+4\,x}} \right ) ^{4}-3\, \left ( -{\it \_C1}/2-1/2\,\sqrt {{{\it \_C1}}^{2}+4\,x} \right ) ^{2}- {\frac {3\,{\it \_C1}}{2}}-{\frac {3}{2}\sqrt {{{\it \_C1}}^{2}+4\,x}} \right ) \left ( -{\frac {{\it \_C1}}{2}}-{\frac {1}{2}\sqrt {{{\it \_C1}}^{2}+4\,x}} \right ) ^{-1}},y \left ( x \right ) ={\frac {x}{6} \left ( 3\, \left ( -{\it \_C1}/2+1/2\,\sqrt {{{\it \_C1}}^{2}+4\,x} \right ) ^{2}+3 \right ) \left ( -{\frac {{\it \_C1}}{2}}+{\frac {1}{2} \sqrt {{{\it \_C1}}^{2}+4\,x}} \right ) ^{-1}}+{\frac {1}{6} \left ( \left ( -{\frac {{\it \_C1}}{2}}+{\frac {1}{2}\sqrt {{{\it \_C1}}^{2}+ 4\,x}} \right ) ^{4}-3\, \left ( -{\it \_C1}/2+1/2\,\sqrt {{{\it \_C1}}^ {2}+4\,x} \right ) ^{2}-{\frac {3\,{\it \_C1}}{2}}+{\frac {3}{2}\sqrt { {{\it \_C1}}^{2}+4\,x}} \right ) \left ( -{\frac {{\it \_C1}}{2}}+{ \frac {1}{2}\sqrt {{{\it \_C1}}^{2}+4\,x}} \right ) ^{-1}} \right \} \]