15. Mohamed is selling tickets for his home movies. Tickets for friends are $3.00 and
everyone else must pay $5.00 per ticket. If he sold
72 tickets and made $258 how many of each type
did he sell?

In order for the function to be linear, what must m be and why? m = 22 because the rate of change is 1. m = 20 because the rate of change is 3. m = 22 because the rate of change is -1. m = 20 because the rate of change is -3.