Respuesta :

3(2-y) + y = 4.50
6 - 3y + y = 4.50
- 2y = -1.5
     y = 0.75

3x + y = 4.50
3x + 0.75 = 4.50
3x = 3.75
x = 1.25

answer
x = 1.25 and y = 0.75
cost of one lemonade = 75 cents