Answer:
Justin travels 211.83 miles on 8.2 gallons of gas.
Explanation:
77.5 miles / 3.1 gallons = x miles / 8.2 gallons
Solve for x... multiply by 8.2 gallons on both sides (that cancels it on the right) side of the equation.
8.2 gallons *77.5 miles / 3.1 gallons = x
635.5/ 3.1 = x
211.83 miles = x