Final answer:
The cost of one large popcorn is $8.25, and the cost of one large soda is $3.50. We found the prices by creating a system of equations based on the given purchases and solving it using the elimination method.
Step-by-step explanation:
To solve the problem of determining the cost of each item (large popcorn and large soda), we set up two equations based on the given purchases of Alexia and Olivia:
- Olivia: 2P + 4S = $30.50
- Alexia: 3P + 2S = $31.75
We can solve this system of equations using either substitution or elimination method. Let's use the elimination method:
- Multiply the second equation by 2 to match the number of sodas in the first equation: 6P + 4S = $63.50
- Subtract the first equation from this new equation: (6P + 4S) - (2P + 4S) = ($63.50 - $30.50)
- Simplify to find the price of popcorn: 4P = $33
- Divide by 4 to find the price of one large popcorn: P = $8.25
- Substitute the price of popcorn back into one of the original equations: 2($8.25) + 4S = $30.50
- Simplify and solve for S: $16.50 + 4S = $30.50, so 4S = $14
- Divide by 4 to find the price of one large soda: S = $3.50
Therefore, the cost of one large popcorn is $8.25 and the cost of one large soda is $3.50.