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

Question

1. 15/45 = 5/x
2. 15/x=45/5
3. 15:45::x:5
4. 15/45=x/5

Answer 1

To express the relationship of the cost of gas as a proportion, given that 15 gallons costs $45, you want to find the cost of 5 gallons, represented by \( x \).

The correct proportion in fractional notation to express this relationship would be:

\[ \frac{15}{45} = \frac{5}{x} \]

So the answer is:

1. \( \frac{15}{45} = \frac{5}{x} \)

This proportion states that the ratio of gallons to cost for 15 gallons should be equal to the ratio of gallons to cost for 5 gallons.