Question

Juan’s has tank is 1/5 full. After he buys 9 gallons of gas, it is 7/10 full. How many gallons can Juan’s tank hold?

Answer 1

18 gallons

Explanation:

Let x represent a full tank, then

`(1)/(5)` x + 9 =
`(7)/(10)` x

Multiply through by 10 to clear the fractions

2x + 90 = 7x ( subtract 2x from both sides )

90 = 5x ( divide both sides by 5 )

18 = x

The tank holds 18 gallons