Realize it maths

Question

A certain cellular phone plan charges $36.00​ per month plus $0.14​ for each minute of usage. The monthly charge is given by the formula , where  represents the number of minutes of usage per month. What is the charge for a month with 400​ minutes of usage? Write your answer to two decimal places as money is traditionally written. 

$ 

Answer 1

For this problem you can determine the monthly charge for 400 minutes by substituting 400 for x and solving the equation:

Monthly charge = 0.14 x + 36

Monthly charge = 0.14 • 400 + 36

Monthly charge= 56 + 36

Monthly charge = $92