Renata wins a $20 gift card to an online music site. After Renata purchases 16 songs, the gift card has a remaining balance of $
0. Which equation represents the relationship between y, the remaining balance on Renata’s gift card, and x, the number of songs purchased? 4x + 5y = –100
5x + 4y = 80
4x + 5y = 16
5x + 4y = 20
From reading the problem we see that y = 0 and x = 16. To find the correct equation, simple plug in the values for x and y for each equation and see which equation is true.
