Firstly, let's assume that the cost of 200 gallons of oil was x before the tax was added. So:
[tex]1.08x = 425.52 \\ x = \frac{425.52}{1.08} \\ x = 394[/tex]
Before the tax was added, the cost of 200 gallons was $394. Now let's find the cost of one gallon of oil.
[tex]394 \div 200 = 1.97[/tex]
Thus, the cost of one gallon of oil before the tax was added is $1.97
