Question

Compute the average rate of change of f(x)=(x+4)/(x-3) over the interval [5,7].

A)4/3
B)7/8
C)-7/8
D)-4/3
(Image attached below)

Answer 1

• C) - 7/8

Explanation:

Average rate of change is:

• [f(7) - f(5)]/(7 - 5)

Find the values and substitute into expression:

• f(7) = (7 + 4)/(7 - 3) = 11/4
• f(5) = (5 + 4)/(5 - 3) = 9/2 = 18/4

Find the rate of change:

• (11/4 - 18/4)/2 = (-7/4)/2 = - 7/8

Correct choice is C