A store has 15 packs of baseball cards with 28 cards inside and 12 packs of football cards with 34 cards inside.
Which pair of expressions could be used to find how many baseball cards and football cards the store has in all?
(12 x 34) and (12 x 28)
(12 x 28) and (15 x 34)
(15 x 34) and (15 x 28)
(15 x 28) and (12 x 34)