Answer:
(x -4)^2 +(y +5)^2 = 2
Explanation:
The equation of a circle centered at (h, k) through point (p, q) is ...
(x -h)^2 +(y -k)^2 = (p -h)^2 +(q -k)^2
Filling in your given numbers gives ...
(x -4)^2 +(y +5)^2 = (5-4)^2 +(-4+5)^2
(x -4)^2 +(y -5)^2 = 2