Question

Please help! :( :(

Answer 1

The slopes of the cars are calculated by dividing the number of miles driven by the amount of gasoline consumed for the trip. 
(Carla) 
                       s = (1200 miles - 840) / 12 gal = 30 miles/gal
(Stanley)
                       s = (1200 miles - 840) / 10 gal = 36 miles/gal
Therefore, Stanley's car has a greater slope which means that for the same amount of gasoline, Stanley's car can travel farther.