The generic equation of the line is:
![H-H0 = m (T-T0)](https://tex.z-dn.net/?f=%20H-H0%20%3D%20m%20%28T-T0%29%20)
Where,
m: slope of the line
(T0, H0): ordered pair belonging to the line.
The slope of the line is:
![m =\frac{H2-H1}{T2-T1}](https://tex.z-dn.net/?f=%20m%20%3D%5Cfrac%7BH2-H1%7D%7BT2-T1%7D%20)
Substituting values we have:
![m =\frac{15-17}{5-3}](https://tex.z-dn.net/?f=%20m%20%3D%5Cfrac%7B15-17%7D%7B5-3%7D%20)
Rewriting:
![m =\frac{-2}{2}](https://tex.z-dn.net/?f=%20m%20%3D%5Cfrac%7B-2%7D%7B2%7D%20)
![m = -1](https://tex.z-dn.net/?f=%20m%20%3D%20-1%20)
Then, choosing an ordered pair we have:
![(T0, H0) :( 5, 15)](https://tex.z-dn.net/?f=%20%28T0%2C%20H0%29%20%3A%28%205%2C%2015%29%20)
Substituting values we have:
![H-15=-(T-5)](https://tex.z-dn.net/?f=H-15%3D-%28T-5%29)
Rewriting the equation:
![H=-T+5+15](https://tex.z-dn.net/?f=H%3D-T%2B5%2B15)
Then, for 8 hours we have:
Answer:
a linear equation to model the relationship between height H of the candle, and T time is:
the candle will be 12 inches after burning 8 hours