The owner of a lemonade stand mixes juice that costs 2 dollars per gallon with juice that costs 7 dollars per gallon. She gets 20 gallons of punch that costs 4 dollars per gallon. How much of each juice does she use?

Respuesta :

Answer:

8 gallons at $7

12 gallons at $2

Step-by-step explanation:

x gallons at $7 with the remaining (20 - x) gallons at $2 to get 20 gallons at $4

x(7) + (20 - x)(2) = 20(4)

Distribute

7x + 40 - 2x = 80

Combine like terms

5x + 40 = 80

Subtract 40 from both sides

5x = 40

Divide both sides by 5

x = 8 gallons at $7

20 - x = 12 gallons at $2