You fill your car with 15 gallons of gas at a cost of $45. Using fractional notation, how do you write a proportion that shows how much 5 gallons of gas will cost? Use x to represent the unknown cost.

Answer 1

Given:
15 gallons of gas costs $45

Let x represent the cost of 5 gallons of gas.

Using the given values, we can set up a proportion:

15 gallons / $45 = 5 gallons / x

To find x, we can cross multiply:

15 * x = 5 * $45

15x = $225

To solve for x, divide by 15:

x = $225 / 15
x = $15

Therefore, 5 gallons of gas will cost $15.