Answer:
Step-by-step explanation:
The given function is
[tex]f(c)=7c[/tex]
Where [tex]c[/tex] represents cars. This function models the profits they make.
Now, as you can deduct already, we can define to different domains, the mathematical one and the reasonable one.
The reasonable domain is about all the useful values to the problem. For example, as we are talking about car, they can't wash -5 cars, so negative numbers are excluded. Similarly, they can't wash 6.75 cars, because that would imply an incomplete job.
Therefore, the domain for this function is [tex]c > 0[/tex] where [tex]c \in Z[/tex].
(Notice that we specify that the independent valur can only use whole positive numbers only).