The graph of f(x) = 2x + 1 is shown below. Explain how to find the average rate of change between x = 0 and x = 3.

7/3 is the average rate of change.

Average rate of change of a function f(x) between any x values a and b = slope of the secant line connecting f(a) and f(b). This means (f(b)-f(a))/ (b-a). If a=0 and b=3, the average rate of change equals (f(3)-f(0))/(3-0).
f(3)=8+1=9, and f(0)= 1+1=2. So the average rate of change is (9-2)/3= 7/3.