Answer:
[tex]7[/tex]
Step-by-step explanation:
We see that the circle is centered at [tex](1, 0)[/tex]. We know that because it's centered on the x-axis, one of the diameters will lie on the x-axis.
We know that the circle intersects the x-axis at [tex](8, 0)[/tex]. Therefore the radius of the circle is the distance between these points, in this case [tex]8-1=7[/tex].
So, the answer is [tex]\boxed{7}[/tex] and we're done!
