Model Contexts with Two Variable Expressions

Question

Need help please!! I have 10 questions due Friday and I have no idea how to do this!! Here’s one:

David is raising money for a school trip by selling packs of cookies and candy bars. The price of each pack of cookies is $1.50 and the price of each candy bar is $1. Yesterday David made $15.50 and sold 2 more packs of cookies than candy bars. Algebraically determine the number of packs of cookies sold and the number of candy bars sold.

Answer 1

Call the number of packs of candy bars sold c

If he sold 2 more packs of cookies than candy bars then this would be c+2

Total sales are c x 1.00 plus (c+2)(1.50) which equals 15.50 so

c + 1.5c +3.00= 15.50

2.5c = 12.50

c=5 which is the number of packs of candy bars

c+2 = 7 which is the number of packs of cookies