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.
Let's assume that the cost of gas is directly proportional to the number of gallons purchased.
We can write a proportion as:
Cost of 15 gallons / Number of gallons = Cost of 5 gallons / Number of gallons
The cost of 15 gallons is $45, and the number of gallons is 15, so we have:
45 / 15 = x / 5
Simplifying the left side of the proportion, we get:
3 = x / 5
To solve for x, we can multiply both sides of the equation by 5:
3 * 5 = x
15 = x
Therefore, 5 gallons of gas will cost $15.
To write a proportion that shows how much 5 gallons of gas will cost, we can set up the following equation:
15 gallons of gas --> $45
5 gallons of gas --> x dollars
Using fractional notation, the proportion can be written as:
(15/45) = (5/x)
Where x represents the unknown cost.