Answer:
-2 units per unit increase in x
Explanation:
The average rate of change of a function f(x) on a given interval [a, b] is:
f(b) - f(a)
a. r. of c. = ----------------
b - a
Here a = -1 and b = +1. The function f(x) is given graphically. Note how f(a) = f(-1) = 4 and how f(b) = f(+1) = 0.
In this case, the a. r. of c. is:
0 - 4 -4
a. r. of c. = ---------------- = ---------- = -2 units per unit increase in x
1 - (-1) 2