What’s the equation of a circle whose radius is 16 units and center is at (2,-5)

Answer 1

The equaton of a circle is (x-a)² + (y-b)² = r²

^{Where (a,b) is a coordinate of the center.}

(x-2)² + (y+5)² = 16²

Answer 2

(x-2)^2 + (y+5)^2 = 16^2

(x^2 -4x + 4 + y^2 + 10y + 25 = 256

x^2 -4x + y^2 + 10y = 227 is an equation of a circle with radius 16 and center (2,-5)

but leave it in

(x-h)^2 + (y-k)^2 = r^2 form and you can read off the center as (h,k) and radius = r