Question

What is the center of the circle x2 + y2 + 11x + 18= 0?

Answer 1

(- 5.5 , 0) is the center

Explanation:

center ( h, k)

Circle: (x-h)² + (y-k)² = r²

x² + y² + 11x + 18= 0

(x² + 11x + 5.5²) + (y - 0)² = 5.5² - 18

(x + 5.5)² + (y - 0)² = 12.25

(x - (-5.5))² + (y - 0)² = 3.5²

h = -5.5 K = 0 r = 3.5