Answer:
Center = (0,0)
Explanation:
The standard form of a circle is
..... (1)
where, (h,k) is the center of the circle and r is radius.
The given equation is

Divide both sides by 3.

..... (2)
On comparing (1) and (2) we get
h=0, k=0, r=5
Therefore, the center of the circle is (0,0) and radius of the circle is 5.