\[ \boxed { {x}^{2}{\frac {{\rm d}^{2}}{{\rm d}{x}^{2}}}y \left ( x \right ) -12\,y \left ( x \right ) =0} \]
Mathematica: cpu = 0.016002 (sec), leaf count = 18 \[ \left \{\left \{y(x)\to c_1 x^4+\frac {c_2}{x^3}\right \}\right \} \]
Maple: cpu = 0.015 (sec), leaf count = 15 \[ \left \{ y \left ( x \right ) ={\it \_C1}\,{x}^{4}+{\frac {{\it \_C2}}{{ x}^{3}}} \right \} \]