Using linear function concepts, it is found that he can correctly determine the hourly rate as follows:
subtract the supply fee, 15 dollars from the total cost, then, divide the difference by the number of hours.
<h3>What is a linear function?</h3>A linear function is modeled by:
In which:
- m is the slope, which is the rate of change, that is, by how much y changes when x changes by 1.
- b is the y-intercept, which is the value of y when x = 0, which can also be interpreted as the initial value of a function that is valid only for
, such as is the case in this problem.
The flat fee is of $15, hence b = 15, then:
Philip uses the service for 3.5 hours for his spring cleaning, and his total is $232, hence when x = 3.5, y = 232, so we use it to find the hourly rate m.
Hence, the correct option is:
subtract the supply fee, 15 dollars from the total cost, then, divide the difference by the number of hours.
You can learn more about linear function concepts at brainly.com/question/24808124