Answer:
[tex]C=18h[/tex]
Step-by-step explanation:
Let
C------> represent the total cost
h-----> represent the number of hours
we know that
[tex]C=18h[/tex] -----> linear direct variation that represent the situation
In this problem the constant of proportionality k is equal to the slope m of the line
so
[tex]m=18\frac{\$}{hour}[/tex]