You have a $75 gift card to use at an electronics store.

Question

You have a $75 gift card to use at an electronics store.

a. You want to use your card to buy 2 DVDs for $15 each and several CDs. Write and

solve an inequality to find the possible amounts of money that you can spend on CDs

using your card.

b. Suppose that CDs cost $11 each. Write and solve an inequality to find the possible

number of CDs that you can buy using the card.

Answer 1

DVDx + CDy ≤ 75 where DVD = price of DVD and CD = price of CD

(a)

15x + CDy ≤ 75

15(2) + CDy ≤ 75 => CDy ≤ 45

(b)

CDy ≤ 45

11y ≤ 45 => y ≤ 45/11 or, as can't buy fractional CDs, y ≤ 4