Using linear functions, it is found that the sales price in Port Townsend is never double the Seattle price.
A linear function has the following format:
![y = mx + b](https://tex.z-dn.net/?f=y%20%3D%20mx%20%2B%20b)
In which:
- m is the slope, which is the rate of change.
- b is the y-intercept, which is the initial value.
For Seattle:
- Initial value of $38,000 in 1970, thus the y-intercept is
.
- Increased by $137,000 in 20 years, thus the slope is:
![m = \frac{137000}{20} = 6850](https://tex.z-dn.net/?f=m%20%3D%20%5Cfrac%7B137000%7D%7B20%7D%20%3D%206850)
Thus, the <u>sales prince in n years after 1970</u> for Seattle is:
![S(n) = 38000 + 6850n](https://tex.z-dn.net/?f=S%28n%29%20%3D%2038000%20%2B%206850n)
For Port Townsend:
- Initial value of $8,400 in 1970, thus the y-intercept is
.
- Increased by $160,000 in 20 years, thus the slope is:
![m = \frac{160000}{20} = 8000](https://tex.z-dn.net/?f=m%20%3D%20%5Cfrac%7B160000%7D%7B20%7D%20%3D%208000)
Thus, the <u>sales prince in n years after 1970</u> for Port Townsend is:
![P(n) = 8400 + 8000n](https://tex.z-dn.net/?f=P%28n%29%20%3D%208400%20%2B%208000n)
Port Townsend is double Seattle in n years after 1970, for which:
![P(n) = 2S(n)](https://tex.z-dn.net/?f=P%28n%29%20%3D%202S%28n%29)
Then
![8400 + 8000n = 2(38000 + 6850n)](https://tex.z-dn.net/?f=8400%20%2B%208000n%20%3D%202%2838000%20%2B%206850n%29)
![8400 + 8000n = 76000 + 13700n](https://tex.z-dn.net/?f=8400%20%2B%208000n%20%3D%2076000%20%2B%2013700n)
![7500n = -67600](https://tex.z-dn.net/?f=7500n%20%3D%20-67600)
Negative number, and we are working only with positive, thus, it is found that the sales price in Port Townsend is never double the Seattle price.
A similar problem is given at brainly.com/question/23861861