\[ a x^2+2 x y(x) y'(x)-y(x)^2=0 \] ✓ Mathematica : cpu = 0.0896696 (sec), leaf count = 41
\[\left \{\left \{y(x)\to -\sqrt {-a x^2+c_1 x}\right \},\left \{y(x)\to \sqrt {-a x^2+c_1 x}\right \}\right \}\] ✓ Maple : cpu = 0.011 (sec), leaf count = 33
\[ \left \{ y \left ( x \right ) =\sqrt {-a{x}^{2}+{\it \_C1}\,x},y \left ( x \right ) =-\sqrt {-a{x}^{2}+{\it \_C1}\,x} \right \} \]