A store sells packages of comic books with a poster. A poster and 6 comics cost $12.75
A poster and 15
comics cost $21.75
Write a linear function rule that models the cost y of a package containing any number x of comic books.
Suppose another store sells a similar package, modeled by a linear function rule with initial value $7.50 Explain which store has the better deal.
The linear function rule is Y = ___