Question

A circle is centered at (−8, −13) and has a radius of 13.

What is the equation of the circle?

Enter the equation in the box using lower case variables x and y.

Answer 1

The answer is
(x+8)²+(y+13)²=169

Answer 2

we know that
the equation of a circle is
(x-h)²+(y-k)²=r²
where
(h,k) is the center
r is the radius
so
for a circle is centered at (−8, −13) and has a radius of 13
the equation is
(x+8)²+(y+13)²=13²--------------> (x+8)²+(y+13)²=169

the answer is
(x+8)²+(y+13)²=169