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.....
We can write the proportion as:
15 gallons / $45 = 5 gallons / x
To find the value of x, we can cross multiply:
15 * x = 5 * $45
15x = $225
x = $225 / 15
x = $15
Therefore, 5 gallons of gas will cost $15.