Final answer:
To output an invoice with the total cost of selected services, list each service with its price, sum those prices, and add any fixed costs. This calculation process pertains to basic business mathematics and is similar to the method used to determine costs for services like word processing or running a barber shop.
Step-by-step explanation:
The question involves calculating the total cost for services rendered, which falls under a business-related math task typically encountered by high school students.To create the invoice for services selected in the example, one would list each service along with its price, and then calculate the total. In the provided example, Davy's auto shop invoice would list Service 1: Oil change at $35, Service 2: Car wax at $12, and then the Total cost would be the sum of these two services, $35 + $12, which equals $47. This is similar to the equation that represents the total cost in Aaron's Word Processing Service, where the total cost is a function of a one-time charge and the cost per hour of service used.Conclusion The main answer formula for total costs, in general, is the sum of fixed costs (one-time fees or standing charges regardless of the number of services used) plus variable costs (costs that vary depending on the quantity of the service used). In creating an invoice, applying this formula helps in providing accurate billing to customers.