The formula for a circle is:
(x-p)^2+(y-q)^2=r^2
The radius is given (r=6), as well as the centre of the circle (-2;3).
"p" and "q" represent the coordinates of the centre of the circle.
So it would look like this -
(x-p)^2+(y-q)^2=r^2
p=x-coordinate (-2)
q=y-coordinate (3)
r=6
(x-(-2))^2+(y-(3))^2 =6^2
(x+2)^2 + (y-3)^2 = 36
***"^" means "to the power of"
Hope this helped~