<PRE><B>Question 417721</B>
begins the trip with 14 gallons of gas in her car.
 The car uses up one gallon of gas every 30 miles.
Let g represent the number of gallons of gas she has left in her tank, and let d
 represent the total distance (in miles) 
:
d = 30(14 - g) 
:
For example, if she uses two gallons, there will be 12 gal left in the tank; g=12
d = 30(14 - 12)
d = 30(2)
d = 60 mi 
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