Answer:
c.$24
Explanation:
to find how much it would cost for 1 gallon, the easiest way to do that is subtract 21 from 18.
21 - 18 = 3
So, it's 3 dollars per gallon. Now that we know that we multiply it by 8 to find how much it would cost.
8 x 3 = 24
Eight gallons of gas would cost 24$ :3