Since the graph is a linear function, we're going to use the slope formula solve this:
Note I am replacing m with k

Inserting 2 points from the graph, let's use (1,8) and (2,16).

k=8
Answer:
(x + 1)^2 + (y - 2)^2 = 3^2 = 9
Step-by-step explanation:
The standard equation of a circle with center at (h, k) and radius r is
(x - h)^2 + (y - k)^2 = r^2.
Here, h = -1, k = 2 and r = 3, so the equation of this particular circle is
(x + 1)^2 + (y - 2)^2 = 3^2 = 9.
First step, divide 6 from both sides.
t/6=r^2+1
second step, subtract 1 from both sides
t/6 -1=r^2
Now take the square root of each side.

Done!