Question

The bill for five glasses of apple juice and four salads is $9.50, but the bill for four glasses of apple juice and five salads is $10.30. What would be the bill for a glass of juice and a salad?

Answer 1

Answer: the bill for a glass of apple juice is $0.7 and the bill for a salad is $1.5

Step-by-step explanation:

Let x represent the bill for a glass of apple juice.

Let y represent the bill for a salad.

The bill for five glasses of apple juice and four salads is $9.50. It means that

5x + 4y = 9.5 - - - - - - - - - - - 1

The bill for four glasses of apple juice and five salads is $10.30. This means that

4x + 5y = 10.30- - - - - - - - - - - -2

Multiplying equation 1 by 4 and equation 2 by 5, it becomes

20x + 16y = 38

20x + 25y = 51.5

Subtracting, it becomes

- 9y = - 13.5

y = - 13.5/-9

y = 1.5

Substituting y = 1.5 into equation 1, it becomes

5x + 4 × 1.5 = 9.5

5x + 6 = 9.5

5x = 9.5 - 6 = 3.5

x = 3.5/5 = 0.7