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.
1.15:45 :: x : 5
2.15/45 = x/5
3.15/45 = 5/x
4.15/x = 45/5
The correct answer is option 3.
Using the provided information, we can set up a proportion to find the unknown cost of 5 gallons of gas. The fraction for the known cost of 15 gallons of gas is 15/45 (15 gallons out of 45 dollars). We can set this equal to the unknown cost of 5 gallons of gas, represented by x, over 5 gallons. So, the proportion is: 15/45 = x/5.
The correct answer is option 3.
Using fractional notation, the proportion that shows how much 5 gallons of gas will cost can be written as:
15/45 = 5/x
The correct proportion that shows how much 5 gallons of gas will cost using fractional notation is option 3: 15/45 = 5/x.
To understand how this proportion is formed, let's break it down step by step:
1. Start with the given information: You filled your car with 15 gallons of gas at a cost of $45.
2. Set up the proportional relationship by writing the ratio of gallons to cost: 15/45.
3. Since you want to find the unknown cost of 5 gallons, you can set up the proportion by adding the unknown cost x and the known gallons: 15/45 = 5/x.
By cross-multiplying and solving for x, you can find the cost of 5 gallons of gas.