what is the center and radius of the circle represented by the following equation: (x+3)^2 + (y-6)^2=81?

When the equation of a circle is in this format:

(x - h)² + (y - k)² = r²     ,

The center of the circle is (h, k) and the radius is r.

 

 

So...if the equation of a circle is:

 

(x + 3)² + (y - 6)² = 81

 

h = -3

 

k = 6

 

r² = 81

r   = \(\sqrt{81}\)

r   = 9

 

The center of the circle is (-3, 6) and the radius is 9.