A group of students washed cars to raise money. The net amount A, in dollars, raised by washing K cars is given by the function A(K)=4K-30. If the group washed 15 cars, what is the net amount they raised?
First, note that A(K) means that there is a function A which represents the net amount of money, in dollars, raised in terms of the number of cars washed (K).
So if the group washed 15 cars, then K=15.
Thus, given that A(K)= 4K - 30 and K= 15 , we are looking to solve for A(15) ...
A(15) = 4(15) - 30 = 60 - 30 = 30
Therefore, if the group washed 15 cars, then they raised a net amount of $30.