Answer: the center is (-5, 5) and the radius is 15
Step-by-step explanation:
the standard form of a circle is
(x-h)^2 + (y-k)^2 = r ^2 where h is the x coordinate and k is the y coordinate of the center of the circle
(h,k) = the center of the circle
r = radius
therefore,
(x+5)^2 + (y-5)^2 = 225 means that x has to be -5 since subtracting a negative creates a positive and y must be 5 as it is negative in the equation
think of it as making the sum/difference 0 within the parentheses:
(x+5) -5+5 = 0 so x=-5
(y-5) 5-5 = 0 so y =5
so the center of the circle is (-5,5)
the radius is simply 225 square rooted which is 15
hope this helps :)