Roxanne's car used 4.8 gallons of gasoline to drive 124 miles. if roxanne has 180 more miles to go, which is closest to the additional number of gallons of gasoline the car will use to complete the trip?

Since Roxanne's car consumes 4.8 gallons of gasoline for 124 miles covered, this means that 1 gallon of gasoline covers 124/4.8 = 310/12 miles.

Now, Roxanne needs to travel further and cover 180 more miles, this means that her car needs 180 ÷ (310/12) = 180(12)/310 ≈6.97 gallons. This means that the car will be consuming approximately 7 more gallons of gasoline to cover the rest of the trip.

7 gallons