Question

Spends a total of $38.75 on 5 drinks and 2 bags of popcorn. Noah spends a total of $37.25 on 3 drinks and 4 bags of popcorn. Write a system of equations that can be used to find the price of one drink and the price of one bag of popcorn.

Answer 1

3d + 4p = $37.25

5d + 2p = $38.75

Actual Answer:

Bag of popcorn is $5

A drink is $5.75

Explanation:

Let drinks = d

Let popcorn = p

Noah: 3d + 4p = $37.25

Other: 5d + 2p = $38.75

Choose a variable to eliminate (We'll choose p)

3d + 4p = $37.25

(5d + 2p = $38.75) -2

Distribute

-10d - 4p = -77.5

The -4p cancels out the 4p, then we combine

-7d = -40.25

Divide both sides by -7

-7d/-7 = -40.25/-7

d = 5.75

Back to 3d + 4p = $37.25

Substitute d with 5.75

3(5.75) + 4p = $37.25

17.25 + 4p = 37.25

Move the constant to the other side

17.25 + 4p = 37.25

-17.25 -17.25

4p = 20

Divide both sides by 4

4p/4 = 20/4

p = 5