\[ \boxed { 9\,y \left ( x \right ) \left ( {\frac {\rm d}{{\rm d}x}}y \left ( x \right ) \right ) ^{2}+4\,{x}^{3}{\frac {\rm d}{{\rm d}x}}y \left ( x \right ) -4\,{x}^{2}y \left ( x \right ) =0} \]
Mathematica: cpu = 0.843107 (sec), leaf count = 454 \[ \left \{\text {Solve}\left [\frac {\sqrt {x^6+9 x^2 y(x)^2} \log \left (\sqrt {x^4+9 y(x)^2}+x^2\right )}{2 x \sqrt {x^4+9 y(x)^2}}+\frac {-x \sqrt {x^4+9 y(x)^2} \log \left (y(x)^2\right )+x \sqrt {x^4+9 y(x)^2} \log \left (x^4+9 y(x)^2\right )-x \sqrt {x^4+9 y(x)^2} \log \left (x^5+9 x y(x)^2\right )-\sqrt {x^6+9 x^2 y(x)^2} \log \left (\frac {x^4}{9 y(x)^2}+1\right )+\sqrt {x^6+9 x^2 y(x)^2} \log \left (\frac {9 y(x)^2}{x^4}+1\right )}{4 \sqrt {x^6+9 x^2 y(x)^2}}=c_1,y(x)\right ],\text {Solve}\left [\frac {x \sqrt {x^4+9 y(x)^2} \log \left (y(x)^2\right )-x \sqrt {x^4+9 y(x)^2} \log \left (x^4+9 y(x)^2\right )+x \sqrt {x^4+9 y(x)^2} \log \left (x^5+9 x y(x)^2\right )-\sqrt {x^6+9 x^2 y(x)^2} \log \left (\frac {x^4}{9 y(x)^2}+1\right )+\sqrt {x^6+9 x^2 y(x)^2} \log \left (\frac {9 y(x)^2}{x^4}+1\right )}{4 \sqrt {x^6+9 x^2 y(x)^2}}-\frac {\sqrt {x^6+9 x^2 y(x)^2} \log \left (\sqrt {x^4+9 y(x)^2}+x^2\right )}{2 x \sqrt {x^4+9 y(x)^2}}=c_1,y(x)\right ]\right \} \]
Maple: cpu = 0.874 (sec), leaf count = 87 \[ \left \{ y \left ( x \right ) =-{\frac {i}{3}}{x}^{2},y \left ( x \right ) ={\frac {i}{3}}{x}^{2},y \left ( x \right ) =-{\frac {1}{6} \sqrt {-4\,{x}^{2}{\it \_C1}+{{\it \_C1}}^{2}}},y \left ( x \right ) ={ \frac {1}{6}\sqrt {-4\,{x}^{2}{\it \_C1}+{{\it \_C1}}^{2}}},y \left ( x \right ) =-2\,{\frac {\sqrt {{x}^{2}{\it \_C1}+9}}{{\it \_C1}}},y \left ( x \right ) =2\,{\frac {\sqrt {{x}^{2}{\it \_C1}+9}}{{\it \_C1}} } \right \} \]