PLEASE HELP ALGEBRA QUESTION

Answer:
6.75
Step-by-step explanation:
The average rate of change of function f(x) on the interval [-4, -2] would be:
f(-2) - f(-4) 18 - 4.5
a. r. c. = -------------------- = --------------- = 13.5/2, or 6.75.
-2 - (-4) 2