The correct answer is:
3 inches up per foot across
Explanation:
To find the rate of change, we must find the change in height and the change in length. The rate of change is then written as rise/run, or
(change in height)/(change in length).
The heights at the two given points are 18 inches and 12 inches. This gives us a change of 18-12 = 6 inches.
The lengths at the two given points are 6 feet and 4 feet. This gives us a change of 6-4 = 2 feet.
This makes our rate of change (6 inches)/(2 feet); this can then be simplified to (3 inches)/(1 foot), which means it goes up 3 inches for every foot of driveway length.
