a) radius= 4 units
b) (x+5)^2+(y-3)^2=4^2
The distance between the x values in the center point and a point included in the graph will give you the radius.
The x values are 4 units apart (-5 to -1) so your radius is 4 units
Circle formula:
(x-h)^2+(y-k)^2=r^2
Where (h,k) is the center point and r is the radius
Replace h with -5, k with 3, and r with 4 to get equation listed in answer above
Hope this helps!!
