A school supply store sold backpacks of two sizes last week: small for $32 each and large for $48 each. The store sold a total of 80 backpacks for a total of $2,880. The system of equations below can be used to find x , the number of small backpacks sold, and y , the number of large backpacks sold. 32x + 48y = 2880x + y = 80