What is the equation of a circle with center (2, −8) and radius 9?
A) (x + 2)2 + (y − 8)2 = 9
B) (x − 2)2 + (y + 8)2 = 9
C) (x + 2)2 + (y − 8)2 = 81
D) (x − 2)2 + (y + 8)2 = 81

D) (x − 2)^2 + (y + 8)^2 = 81

Step-by-step explanation:

The equation of a circle can be given by

(x-h)^2 + (y-k)^2 = r^2

where (h,k) is the center and r is the radius

We know the center is (2,-8) and the radius is 9

(x-2)^2 + (y--8)^2 = 9^2

(x-2)^2 + (y+8)^2 = 9^2

(x-2)^2 + (y+8)^2 = 81

Equation is  (x - 2)² + (y + 8)² = 81

Step-by-step explanation:

Equation is (x - 2)² + (y - -8)² = 9²

⇒ (x - 2)² + (y + 8)² = 81

not sure but it may be b, as i said i'm not sure.

the answer is 13

step-by-step explanation:

5*5=25

12*12=144

25+144=169

169^2=13