Answer:
centre = (3, - 7 )
Explanation:
The equation of a circle in standard form is
(x - h)² + (y - k)² = r²
where (h, k ) are the coordinates of the centre and r is the radius
(x - 3)² + (y + 7)² = 121 ← is in standard form
with centre = (h, k ) = (3, - 7 )