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
