Find the center and radius of (x+3)^2 + (y+8)^2 = 169

Find the center and radius of (x+3)^2 + (y+8)^2 = 169
A. (-3, -8); 13
B. (-8, 3); 13
C. (3, 8); 13
D. (-8, -3); 169

A. (-3, -8); 13

Same as when you find solutions to a factorised quadratic. Take the x bracket for example and set it = to 0
(x+3)^2=0
(x+3)=0 (since square root of 0 is still)
x= -3

Same for y
y=-8

And the radius is the square root of the circle equation. So Sqr169 = 13

(x - a)^2 + (y - b)^2 = r^2, where centre (a, b) and radius r

so is A

OPTION A