Amоrphоus Selenium is а ___________ used in direct DR.
While оn а fаll breаk trip, a grоup оf friends burns [G] gallons of gas in the first [m] miles, then stops to refuel. If they have [M] miles yet to drive, how many gallons of gas do they need to make it there without stopping for gas again? Assuming the tank is big enough to hold whatever they need. (Leave your answer in whole number form)