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

Question

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

Answer 1

Let x be the cost of 5 gallons of gas.

We know that 15 gallons of gas cost $45.

So, we can set up a proportion as follows:

15 gallons / $45 = 5 gallons / x

Simplify the proportion:

15/45 = 5/x

Divide both sides by 15:

1/3 = 5/x

Cross multiply:

1x = 15

x = $15

Therefore, 5 gallons of gas will cost $15.