Question

The cost of buying gas varies directly with the number of gallons

Suppose that Lena bought 12.2 gallons of gas for $35.99. Write an equation that could be
used to find the unit cost per gallon of gas. Then find out how much 9.5 gallons of gas
would cost. Round to the nearest cent.

Answer 1

1 gallon of gas is $2.95

9.5 gallons of gas is $28.025

Explanation:

`(12.2)/(35.99) =(1)/(y)`

Cross Multiply.

12.2 · y = 1 · 35.99

12.2y = 35.99

12.2y ÷ 12.2 = 35.99 ÷ 12.2

y = 2.95

1 gallon of gas is $2.95.

`(1)/(2.95) =(9.5)/(y)`

1 · y = 2.95 · 9.5

y = 28.025

9.5 gallons of gas is $28.025.