Answer:
Option B) 18, ![g = 18 - 2h](https://tex.z-dn.net/?f=g%20%3D%2018%20-%202h)
Step-by-step explanation:
We are given the following:
Number of hours spent driving (h): 3 5 7 9
Amount of gas left in tank (g): 12 8 4 0
We have to find the equation that models the amount of gas left in the car as Phan drives.
We can find the equation with the help of two-point form of equation of straight line.
The equation of line is given by:
where,
is the point through which the line passes.
(9,0), (7,4)
The equation of line is:
![(g-0) = \displaystyle\frac{4 - 0}{7-9}(h-9)\\\\-2g = 4h - 36\\\Rightarrow g = 18 - 2h](https://tex.z-dn.net/?f=%28g-0%29%20%3D%20%5Cdisplaystyle%5Cfrac%7B4%20-%200%7D%7B7-9%7D%28h-9%29%5C%5C%5C%5C-2g%20%3D%204h%20-%2036%5C%5C%5CRightarrow%20g%20%3D%2018%20-%202h)
Gallons of gasoline required to fill the tank =
we put h = 0 in the equation.
![g = 18 - 2h\\g = 18-2(0)\\g = 18](https://tex.z-dn.net/?f=g%20%3D%2018%20-%202h%5C%5Cg%20%3D%2018-2%280%29%5C%5Cg%20%3D%2018)
Thus, 18 gallons of gasoline is required to fill up the tank.
Option B) 18, ![g = 18 - 2h](https://tex.z-dn.net/?f=g%20%3D%2018%20-%202h)