The average rate is given by
(f(b) - f(a))/(b-a)
Section A
a = 0
b = 1
f(x) = 5.x
f(a) = 5.0 = 0
f(b) = 5.1 = 5
Then
5 - 0 / 1 - 0 = 5/1 = 5
Section B
a = 2
b = 3
f(a) = 5.2 = 10
f(b) = 5.3 = 15
15-10 / 3 - 2 = 5
Since, f(x) is a linear equation with slope = 5, its rate of change is constant. Thus, both rates (Section A & B) are equal to 5.
