\[ \boxed { x{\frac {\rm d}{{\rm d}x}}y \left ( x \right ) -\sqrt { \left ( y \left ( x \right ) \right ) ^{2}+{x}^{2}}-y \left ( x \right ) =0} \]
Mathematica: cpu = 0.021503 (sec), leaf count = 13 \[ \left \{\left \{y(x)\to x \sinh \left (c_1+\log (x)\right )\right \}\right \} \]
Maple: cpu = 0.031 (sec), leaf count = 27 \[ \left \{ {\frac {1}{{x}^{2}}\sqrt { \left ( y \left ( x \right ) \right ) ^{2}+{x}^{2}}}+{\frac {y \left ( x \right ) }{{x}^{2}}}-{\it \_C1}=0 \right \} \]