CPM Homework Help : CCG Problem 12-24

Describe each circle by finding the center and radius. You need to “complete the square” to rewrite the equation in part (b) in graphing form.

$(x-2)^2+(y+3)^2=25$
Hint (a):
The equation for a circle is $(x − h)^2 + (y − k)^2 = r^2$
where $(h, k)$ is the center of the circle.

$x^2 + 2x + y^2 + 6y – 6 = 0$
Hint (b):
Put the equation into graphing form then refer to part (a) for help.
Answer (b):
$(−1,−3)$ , $r = 4$