We have the following situation:
1. Kaylin bought a soda and two bags of popcorn for $3.00, and we can represent it as follows:
• Let s be the cost per soda (one variable):
,
• Let b be the cost per bag of popcorn (the other variable):
![1s+2b=3.00](https://img.qammunity.org/2023/formulas/mathematics/college/uf8erfuupxh1ku0qnx4l35uo76oq76nuw0.png)
2. Her brother bought three sodas and a bag of popcorn for $6.50. Using the same variables, we have:
![3s+1b=6.50](https://img.qammunity.org/2023/formulas/mathematics/college/wnienn5uswsbr5t6qgnnozw5sq14l4ma0l.png)
3. Now, we can solve this system of equations by substitutioh