posted by lindsay .
Write an equation for each circle if the coordiantes of the center and length of the radius are
a. center(-1,-5) radius = 2 units
b. center(0,3) radius = 7 units
c. center(-9,7) radius = 1/2 units
(x-h)^2 + (y-k)^2 = r^2
where (h,k) is the center, r is the radius.
If you get stuck, come on back and show how far you got. Watch those pesky - signs.