Answer:
5/2
Step-by-step explanation:
Since it's linear, you don't need more than 2 points.
To find the slope, or rate of change, just divide the change in y by the change in x. If (-5, 18) is (x1, y1) and (-3, 23) is (x2, y2):
The rate of change is 5/2. If you want to be extra sure, check it with 2 other points: