Question

Changs gas tank is 1/5 full. After he buys 13 gallons of gas, it is 7/10 full. How many gallons can Changs tank hold?

Answer 1

26 gallons

Explanation:

Set up an equation to represent this problem. Parameter (x) represents the gas tank when it is filled. Based on the problem;

`(1)/(5)x + 13 = (7)/(10)x`

Inverse operations;

`(1)/(5)x + 13 = (7)/(10)x\\-(1)/(5)x\\\\13 = (7)/(10)x - (1)/(5)x\\\\`

Convert to combine denominator, and simplify,

`13 = (7)/(10)x - (1)/(5)x\\\\13 = (7)/(10)x - (2)/(10)x\\\\13 = (5)/(10)x\\\\13 = (1)/(2)x`

Inverse operations,

`13 = (1)/(2)x\\*2\\\\26 = x`

26 gallons