Question

Macy doesn’t have any money in her bank account, but begins saving $15 each week. Robby has $20 in his bank account and saves $10 each week.



Which system of equations models this situation?


y = 15

y = 10 + 20x


y = 15x + 20 + 10x

y = 15x

y = 20 + 10x


y = 15x + 20

y = 10x

Answer 1

To model the situation with a system of equations, we need to establish equations for both Macy and Robby based on their savings over time.

1. **Macy**: She starts with $0 and saves $15 each week. Therefore, her savings after \(x\) weeks can be represented by the equation:
\[
y = 15x
\]

2. **Robby**: He starts with $20 and saves $10 each week. Therefore, his savings after \(x\) weeks can be represented by the equation:
\[
y = 10x + 20
\]

Combining these two equations, we get the system of equations that models this situation:
- \(y = 15x\) (for Macy)
- \(y = 10x + 20\) (for Robby)

Thus, the correct option from your provided choices is:
\[
y = 15x \\
y = 10x + 20
\]