Question

Write the standard equation of a circle with center (-9,-4) and radius 15.

(x + 9)2 + (y + 4)2 = 5
(x + 4)2 + (y + 9)2 = 5
(x - 4)2 + (y- 9)2 = 5
(x - 9)2 + (y - 4)2 = 5

Answer 1

Equation of a circle:

radius = the sq. rt of (x - h)^2 + (y - k)^2

Plug in the values for the center of a circle and the radius:

15 = the sq. rt of (x + 9)^2 + (y + 4)^2

(x + 9)^2 + (y + 4)^2 = 225

The answer is A or the first one.