Answer:
O : (-3,-4.5)
Explanation:
center of circle: O (x.y)
Radius (r) = OA = OB = OC
r² = (x - (-1))² + (y - (-2))² ---- OA²
r² = (x - (-5))² + (y - (-2))² ---- OB²
r² = (x - (-1))² + (y - (-7))² ---- OC²
OA²=OB² : (x - (-1))² + (y - (-2))² = (x - (-5))² + (y - (-2))²
(x+1)² - (x+5)² = 0 x²+2x+1-x²-10x-25 = 0
8x = -24
x = -3
OA² = OC² (x - (-1))² + (y - (-2))² = (x - (-1))² + (y - (-7))²
y²+4y+4 = y² +14y +49
10y = -45
y = - 4.5
O : (-3,-4.5)