Damian filled up his car with gas before embarking on a road trip across the country. The car uses 2 gallons of gas for every hour driven, and after driving for 3 hours, there were 6 gallons of gas left in the tank. Write an equation for the function

G

(

t

)

,

G(t), representing the number of gallons of gas remaining in Damian's gas tank after

t

t hours of driving.