Maya and her friends are planning a car wash event. Maya creates a function C(x) to model the group's costs for washing x cars and a function R(x) to model the revenue the group will make from washing x cars. The net profit the group will earn is represented by the function P(x) = -60 + 4.5x, which is equal to R(x) - C(x). Select the two functions that could represent the cost and revenue for the car wash.

Step-by-step explanation:

The answer is C.

That's another way of using the vertical line test. Put a ruler perpendicular to the x axis and going through a point. If the ruler hits only one point, then then if all the points plotted do the same thing, then the points make a function.

C says the same thing. Only 1 element in the domain (x) can be associated with 1 y value (the range). If there is more than 1 y value, then you do not have a function.