Answer:
the origin (0, 0)
Explanation:
The equation of a circle centred at the origin has the form
x² + y² = r² ← r is the radius of the circle
Given
x² + y² - 49 = 0 ( add 49 to both sides )
x² + y² = 49 ← in standard form
with centre (0, 0 ) and r = 7