Question

At a fast-food joint, 3 cheeseburgers and 5 medium shakes cost $14.31. At the same fast-food joint, 7 cheeseburgers and 2 medium shakes cost $15.41. What is the cost of a cheeseburger? What is the cost of a medium shake?

PLEASE SHOW ME THE STEPS TO SOLVE THE PROBLEM!

Answer 1

Setup
3c + 5s = 14.31 - multiply by 2
7c + 2s = 15.41 - multiply by -5

6c + 10s = 28.62
-35c -10s = -77.05 - Add together

-29c = -48.43
c = 1.67 - Cost of Cheeseburger

Plug in
3(1.67) + 5s = 14.31
5.01 + 5s = 14.31
5s = 9.30
s = 1.86 - Cost of a medium shake