Answer:
You will break even on the car wash when you buy 13.5 gallons. As long as you buy that or more, it is cheaper to get the car wash.
Step-by-step explanation:
In order to find this, we need to create equations for both situations. If we let x equal the amount of gallons purchased, we can model the first equation as:
f(x) = 3.35x
And the second equation as:
f(x) = 3.05x + 4.05
Then to find when they equal each other, we can set the two equations equal to each other and solve for x.
3.35x = 3.05x + 4.05
0.30x = 4.05
x = 13.5
This means once you buy 13.5 gallons, the prices will be the same. Any amount over that and the car wash will be cheaper
