Answer
See below.
Work Step by Step
The standard form of the equation of a circle is:
$(x-a)^2+(y-b)^2=r^2$
where $(a,b)$ is the center of the circle and $r$ is the radius.
Hence, here we have:
$x^2+y^2-0.5x+0.5y=0.125\\(x-0.25)^2-0.25^2+(y+0.25)^2-0.25^2=0.125\\(x-0.25)^2+(y+0.25)^2=0.25=0.5^2$
Thus, the center is at $(0.25,-0.25)$ and the radius is $0.5$.