Answer:
x^2 + y^2 = 49
Step-by-step explanation:
The equation of a circle is given by
( x-h) ^2 + (y-k) ^2 = r^2
(h,k) is the center of the circle and r is the radius
The circle is centered and (0,0) and the radius is 7
( x-0) ^2 + (y-0) ^2 = 7^2
x^2 + y^2 = 49
