Question

Alica bought two burgers and three small fries at Dave's Burger shack for a total of $21.18.

Jack bought four burgers and two small fries for a total of $29.56.
How much does each item cost individually?

Answer 1

Answer: fries=$3.20, burgers=$5.79

Explanation:

1. form equations for each person
2. set them up one below the other
3. solve for one unknown
4. plug in that answer into one of the equations to get the other unknown

(f=fries, b=burger)

21.18=2b+3f

29.56=4b+2f

-2(21.18=2b+3f)

29.56=4b+2f

-42.36=-4b-6f

29.56=4b+2f

-12.8=-4f

3.2=f

21.18=2b+3(3.2)

21.18=2b+9.6

-9.6 -9.6

11.58=2b

5.79=b