Answer:
(- 5.5 , 0) is the center
Step-by-step 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
