Find the center h k and radius r of the circle with the give

Find the center (h, k) and radius r of the circle with the given equation.

x^2+ 4x + 4 + y^2 - 8y + 16 = 49

Solution

x²+ 4x + 4 + y² - 8y + 16 = 4

(x²+ 2*2*x + 2²) + (y² - 2*4*y + 4²) = 4

(x + 2)² + (y - 4)² = 2²

(x - (-2))² + (y - 4)² = 2²

(x - h)² + (y - k)² = r² is the equation of circle with centre (h,k) and radius r

centre =(-2,4), radius =2 units