Well whats theproblem so we can figure it out?
Mr Green: 
Mrs Green: 
Keith: 
Kevin: 
Thus Mrs Green and Keith has the expression that is equivalent to
'24a + 16b + 8'
Hope that helps!
Answer:
The center is (0,0) and the radius is 6
Step-by-step explanation:
The equation for a circle can be written in the form
(x-h)^2 + (y-k)^2 = r^2
Where (h,k) is the center and r is the radius
x^2+y^2=36
can be written as
(x-0)^2+(y-0)^2=6^2
The center is (0,0) and the radius is 6