It is ~ 100 miles of mostly interstate driving to camp. Using your model from parts (b) and (c), how much does it cost me to drive to camp if I drive 55 mph, 65 mph, and 75 mph? (don’t forget the return trip)

the current price of gas for part c is 3.89/gal

I have tried to plug things in but I can't figure it out.

again, what is the model?