Question 854512
For a circle centered at the coordinants (a,b) with a radius of r, the equation is
(1) (x-a)^2 + (y-b)^2 = r^2
In your example we have
(2) (a,b) = (2,0) and 
(3) r = 5
Put (2) and (3) into (1) and get the answer
(4) (x-2)^2 + y^2 = 25