\[ \boxed { y \left ( x \right ) \left ( {\frac {\rm d}{{\rm d}x}}y \left ( x \right ) \right ) ^{2}-4\,{a}^{2}x{\frac {\rm d}{{\rm d}x}}y \left ( x \right ) +{a}^{2}y \left ( x \right ) =0} \]
Mathematica: cpu = 0 (sec), leaf count = 0 \[ \text {Hanged} \]
Maple: cpu = 0.577 (sec), leaf count = 181 \[ \left \{ -{\frac {{\it \_C1}\,x}{ay \left ( x \right ) }{\frac {1}{ \sqrt [3]{{\frac {a}{y \left ( x \right ) } \left ( 2\,ax+\sqrt {4\,{a}^{ 2}{x}^{2}- \left ( y \left ( x \right ) \right ) ^{2}} \right ) }}}}{ \frac {1}{\sqrt [3]{{\frac {{a}^{2}}{ \left ( y \left ( x \right ) \right ) ^{2}} \left ( 2\,{a}^{2}{x}^{2}+\sqrt {4\,{a}^{2}{x}^{2}- \left ( y \left ( x \right ) \right ) ^{2}}ax- \left ( y \left ( x \right ) \right ) ^{2} \right ) }}}}}+x=0,-{\frac {{\it \_C1}\,x}{ay \left ( x \right ) }{\frac {1}{\sqrt [3]{-{\frac {a}{y \left ( x \right ) } \left ( -2\,ax+\sqrt {4\,{a}^{2}{x}^{2}- \left ( y \left ( x \right ) \right ) ^{2}} \right ) }}}}{\frac {1}{\sqrt [3]{-4\,{\frac {{ a}^{2} \left ( -2\,{a}^{2}{x}^{2}+\sqrt {4\,{a}^{2}{x}^{2}- \left ( y \left ( x \right ) \right ) ^{2}}ax+ \left ( y \left ( x \right ) \right ) ^{2} \right ) }{ \left ( y \left ( x \right ) \right ) ^{2}}}}}}} +x=0 \right \} \]