Question

Juan and Adam go to the movie theater and purchase refreshments for their friends,

Juan spends a total of $130.00 on 10 bags of popcorn and 10 drinks.
Adam spends a total of $56.50 on 3 bags of popcorn and 5 drinks.
Write a system of equations that can be used to find the price of one bag of popcorn
and the price of one drink.
Using these equations, determine and state the price of a drink, to the nearest cent.

Answer 1

10x + 10y = $130.00

3x + 5y = $56.50

Solution: x=4.25 and y=8.75

Explanation:

The variable x will be used here to show the price of each bag of popcorn, while y will be used to represent the price of each drink. First we can solve 10x + 10y = 130 for x:

10x + 10y = 130

10x + 10y + -10y = 130 - 10y (Subtract 10y from both sides)

10x = -10y + 130

Now divide 10 by both sides

x = -y + 13

Next, you will substitute -y + 13 for x in 3x + 5y = 56.5:

3x + 5y = 56.5

3(-y + 13) + 5y = 56.5

2y + 39 = 56.5 (Simplify both sides of the equation)

2y + 39 + −39 = 56.5+ −39 (Add -39 to both sides)

2y = 17.5 (Now divide both sides by 2)

y = 8.75

You can check this by substituing 8.75 for y in x = -y + 13

Answer 2

Popcorn = $4.25 per bag, Drink = $8.75

Explanation:

p = popcorn

d = drinks

10p + 10d = 130

3p + 5d = 56.50

multiply the second equation by -2 and then solve by elimination

-6p - 10d = -113

4p = 17

p = 4.25

3(4.25) + 5d = 56.50

5d = 43.75

d = 8.75