\[ \boxed { {\it d4y} \left ( x \right ) +10\,f{\frac {{\rm d}^{2}}{{\rm d}{x}^{2}}}y \left ( x \right ) +10\,{\it df}\,{\frac {\rm d}{{\rm d}x}}y \left ( x \right ) + \left ( 3\,{f}^{2}+3\,{\it ddf} \right ) y \left ( x \right ) =0} \]
Mathematica: cpu = 0.014502 (sec), leaf count = 45 \[ \text {DSolve}\left [y(x) \left (3 f''(x)+3 f(x)^2\right )+10 f'(x) y'(x)+10 f(x) y''(x)+y^{(4)}(x)=0,y(x),x\right ] \]
Maple: cpu = 0.0 (sec), leaf count = 41 \[ \left \{ y \left ( x \right ) =\sum _{{\it \_a}=1}^{4}{{\rm e}^{{\it RootOf} \left ( {{\it \_Z}}^{4}+10\,f{{\it \_Z}}^{2}+10\,{\it df}\,{ \it \_Z}+3\,{f}^{2}+3\,{\it ddf},{\it index}={\it \_a} \right ) x}}{ \it \_C}_{{{\it \_a}}} \right \} \]