Question

The cost of a long-distance telephone call is given by the function below, where m is the length of the call in minutes.

C(m) = 0.1m + 1

Determine how long a phone call can be made for $5.50.
A. 40 minutes
B. 90 minutes
C. 45 minutes
D. 50 minutes

Answer 1

45 minutes

Step-by-step explanation

using the equation C(m) = 0.1m + 1, C(m) is the cost of the phone call (5.50)

5.50 = 0.1m + 1 subtract 1 from both sides

4.5 = 0.1m divide both sides by 0.1

45 = m

m is the number of minutes, so 45 minutes