Atheater company charges $4.50 per ticket for people of all age groups. if c represents the total number of children who bought tickets and a represents the total number of adults who bought tickets, which expression best represents the total money earned by the company from the sale of tickets

If one child bought a ticket, we would calculate the total cost by multiplying $4.50 by 1.  If two children bought tickets, we could calculate the total cost by multiplying the total cost by 2.  So, the total number of tickets will always be 4.50 * the total number of tickets.

Because the number of children who bought tickets is represented by c and the number of adults who bought tickets are represented by a, our equation should look like:

$4.50c + $4.50a = money earned