The Shaffer family started on a trip in their car with 18 gallons of gasoline. The car uses 2 gallons of gasoline every hour. If t represents the number of hours spent driving and g represents the number of gallons of gasoline left in the car, which equation could be used to calculate the value of g, if 0 ≤t ≤9
Multiple Choice
g = 18 - 2t
g = 18t - 2
g = 2t - 18 g = 2t + 18