Answer:
(-6, -2)
radius = 5 units
Explanation:
see attached for reference
recall that the general form for an equation of a circle looks something like:
x² + y² + Cx + Dy + E = 0, where
if (h,k) are the coordinates of the center of the circle,
h = - C/2 and k = -D/2
In our case, we are given:
x² + y² + 12x + 4y + 15 = 0
IF we compare this with the general equation above, we can see that
C = 12, D = 4 and E = 15
hence,
h = - C/2 = - (12/2) = -6
k = - D/2 = -4/2 = -2
Hence (h, k) = (-6, -2)
also, the radius is given by the equation
r² = (1/4)(C² + D²) - E
= (1/4)(12²+4²) - 15
= 40-15
= 25
r = ±√25
= ±5 (ignore negative because radius is always positive)
= 5