Answer:
( x-2)^2 + ( y+1) ^2 = 25
Explanation:
The equation of a circle is
( x-h)^2 + ( y-k) ^2 = r^2 where ( h,k) is the center and r is the radius
The center is ( 2,-1) and the radius is the difference from the center to a point on the circle
(2,4) and (2,-1)
since x is the same the radius is (4- -1) = 5
( x-2)^2 + ( y--1) ^2 = 5^2
( x-2)^2 + ( y+1) ^2 = 25