A theater group is having a carwash fundraiser. the group can only spend ​$39 on​ soap, which is enough to wash 40 cars. each car is charged ​$5. ​a) if c is the total number of cars washed and p is the​ profit, which is the independent variable and which is the dependent​ variable? ​b) is the relationship between c and p a​ function? explain. ​c) write an equation that shows this relationship. ​d) find a reasonable domain and range for the situation.