Let's solve the problems step by step.
Problem 1: Tommy the Cat
Part A: Start with the information given. At the start of the week (day 0), Tommy has stolen 5 hair ties, and he steals 3 more each day. We can write the linear equation:
- Initial amount of hair ties = 5
- Daily increase = 3 hair ties per day
The total number of hair ties after \(d\) days can be represented by: \[ h(d) = 5 + 3d \]
Part B: To find out how many hair ties Tommy has stolen after 9 days:
\[ h(9) = 5 + 3(9) = 5 + 27 = 32 \]
So, Tommy would have stolen 32 hair ties after 9 days.
Problem 2: Penny and the Reward
Part A: Penny spends $12 each week, and after 4 weeks she has $134 left.
- The slope \(m\) of the linear function indicating how much money she has left can be described as the negative amount she spends per week. Therefore:
\[ m = -12 \]
- One point we know is the amount she has after 4 weeks, which is given as (4, 134).
Part B: To write a linear equation that models the total money left \(y\) after \(x\) weeks, we start with the slope-intercept form \(y = mx + b\).
Given:
- Slope \(m = -12\)
- After 4 weeks, she has $134 left, so we need to find the y-intercept \(b\).
Using the point (4, 134):
\[ 134 = -12(4) + b \] \[ 134 = -48 + b \] \[ b = 134 + 48 = 182 \]
So, the equation becomes:
\[ y = -12x + 182 \]
Final Answers
-
Tommy the Cat:
- Part A: \( h(d) = 5 + 3d \)
- Part B: 32 hair ties after 9 days.
-
Penny and the Reward:
- Part A:
- \( m = -12 \)
- A point that we know is \( (4, 134) \)
- Part B: \( y = -12x + 182 \)
- Part A: