Answer:
Formula: (x^2 -h) +(y^2 -k)=r^2
The number on the right side of the = is the radius of the circle squared.
(h,k) is the center of the circle.
Let's start with the x coordinates.
-8 is on the left, and -4 to the right, so that will help organize this.
the line goes from -8,-9 to -4,-8. it moved 4 over the x axis and rose 1 over the y axis.
rise/run so 1/4 is the slope.
y=(1/4)x - 7