Answer: If I'm viewing your image properly then the rate of change (slope) is 7/8.
Explanation:
First find 2 coordinates that are on the line, in this case it is
(0, 6) & (-8, -1)
Then using the slope formula
(y2 - y1) / (x2 - x1)
=
(-1 - 6) / (-8 - 0)
=
-7 / -8
=
7/8
