A heating company charges $60 per hour plus $54 for a service call. Let n be the number of hours the technician works at your house.
The cost function C(n) where n is the number of hours is:
C(n) = Hourly Rate * hours + Service Call Charge
C(n) = 60n + 54
The cost function C(n) where n is the number of hours is:
C(n) = Hourly Rate * hours + Service Call Charge
C(n) = 60n + 54