To write a proportion that shows how much 5 gallons of gas will cost, we can use the relationship between the number of gallons and their cost.
The initial information tells us that 15 gallons of gas costs $45. We want to find the cost \( x \) for 5 gallons. The correct proportion in fractional notation can be set up as follows:
\[ \frac{15}{45} = \frac{5}{x} \]
Thus, the correct response from your options is:
Start Fraction 15 over 45 End Fraction equals Start Fraction 5 over x End Fraction.