Question

The Wagaman family bought 4 cheeseburgers and 3 orders of fries for a total of $10.75. The Petry family bought 5 cheeseburgers and 2 orders of fries for a total of $11.25. Write and solve a system to find the cost of a single cheeseburger and single order of fries.

Answer 1

A single cheeseburger order cost $1.23

A single fries order cost $1.28

Explanation:

Let the cost of cheeseburgers be c and the cost of fries be f

Mathematically;

4c + 3f = 10.75 ••••(i)

Secondly;

5c + 2f = 11.2 ••••(ii)

We have two equations to solve simultaneously;

Multiply i by 2 and ii by 3

8c + 6f = 21.5

15c + 6f = 33.6

Subtract ii from i

-7c = -12.1

c = 1.73

Recall;

5c + 2f = 11.2

5(1.73) + 2f = 11.2

2f = 11.2-8.65

2f = 2.55

f = 2.55/2

f = 1.28