\[ 4 x^3 y'(x)-4 x^2 y(x)+9 y(x) y'(x)^2=0 \] ✓ Mathematica : cpu = 0.430162 (sec), leaf count = 197
\[\left \{\text {Solve}\left [\frac {\sqrt {x^6+9 x^2 y(x)^2} \left (\log \left (1-\frac {x^2}{\sqrt {x^4+9 y(x)^2}}\right )-\log \left (\frac {x^2}{\sqrt {x^4+9 y(x)^2}}+1\right )\right )}{4 x \sqrt {x^4+9 y(x)^2}}+\frac {1}{2} \log (y(x))=c_1,y(x)\right ],\text {Solve}\left [\frac {\sqrt {x^6+9 x^2 y(x)^2} \left (\log \left (\frac {x^2}{\sqrt {x^4+9 y(x)^2}}+1\right )-\log \left (1-\frac {x^2}{\sqrt {x^4+9 y(x)^2}}\right )\right )}{4 x \sqrt {x^4+9 y(x)^2}}+\frac {1}{2} \log (y(x))=c_1,y(x)\right ]\right \}\]
✓ Maple : cpu = 0.299 (sec), leaf count = 87
\[ \left \{ y \left ( x \right ) =-{\frac {i}{3}}{x}^{2},y \left ( x \right ) ={\frac {i}{3}}{x}^{2},y \left ( x \right ) =-{\frac {1}{6}\sqrt {-4\,{\it \_C1}\,{x}^{2}+{{\it \_C1}}^{2}}},y \left ( x \right ) ={\frac {1}{6}\sqrt {-4\,{\it \_C1}\,{x}^{2}+{{\it \_C1}}^{2}}},y \left ( x \right ) =-2\,{\frac {\sqrt {{\it \_C1}\,{x}^{2}+9}}{{\it \_C1}}},y \left ( x \right ) =2\,{\frac {\sqrt {{\it \_C1}\,{x}^{2}+9}}{{\it \_C1}}} \right \} \]