\[ \left (x^2-a^2\right ) y'(x)^2+2 x y(x) y'(x)+y(x)^2=0 \] ✓ Mathematica : cpu = 0.0305393 (sec), leaf count = 27
DSolve[y[x]^2 + 2*x*y[x]*Derivative[1][y][x] + (-a^2 + x^2)*Derivative[1][y][x]^2 == 0,y[x],x]
\[\left \{\left \{y(x)\to \frac {c_1}{a-x}\right \},\left \{y(x)\to \frac {c_1}{a+x}\right \}\right \}\] ✓ Maple : cpu = 0.02 (sec), leaf count = 23
dsolve((-a^2+x^2)*diff(y(x),x)^2+2*x*y(x)*diff(y(x),x)+y(x)^2 = 0,y(x))
\[y \left (x \right ) = \frac {c_{1}}{a -x}\]