Question

find the center (h,k) and radius of the circle with the given equation.
x^2+y^2-18x-2y+82=64

Answer 1

x^2+y^2-18x-2y+82=64 = (x-9)^2 + (y-1)^2 = 64 = 8^2

Center (9 , 1 )  radius = 8

Answer 2

x² + y² - 18x - 2y + 82 = 64
                             -82   -82
        x² + y² - 18x - 2y = -28