Question

In year 1, a house is worth 500000. Due to a recession, the house’s value drops to 410000 in year 6.

Write the rule to model the value of the house.

Answers

GPT-4o mini
To model the value of the house over time, we need to establish a function that shows how the house’s value decreases from year 1 to year 6. We have the following points:

- At Year 1: \( V(1) = 500000 \)
- At Year 6: \( V(6) = 410000 \)

We can use a linear function to model the value of the house since we have two points. A linear function can be expressed in the form:

\[
V(t) = mt + b
\]

where \( V(t) \) is the value of the house at year \( t \), \( m \) is the slope (the rate of change), and \( b \) is the y-intercept (initial value at \( t = 1 \)).

1. **Find the slope (m):**
The slope \( m \) can be calculated as follows:

\[
m = \frac{V(6) - V(1)}{6 - 1} = \frac{410000 - 500000}{6 - 1} = \frac{-90000}{5} = -18000
\]

2. **Find the initial value (b):**
Since the initial value \( V(1) = 500000 \) (at year 1), we can directly use this as the y-intercept.

Now we can plug \( m \) and \( b \) into the linear function:

\[
V(t) = -18000t + b
\]

To determine \( b \), we first rewrite it in terms of \( t \) at \( t = 1 \) to calculate:

\[
V(1) = -18000(1) + b = 500000 \\
-18000 + b = 500000 \\
b = 500000 + 18000 \\
b = 518000
\]

3. **Final model:**
Now we plug this value back in to get the function:

The rule modeling the value of the house is:

\[
V(t) = -18000t + 518000
\]

Keep in mind that this model is linear and valid from Year 1 onwards, but the specific behavior of house values may vary according to other factors not incorporated into this simple model.