During the 600 mile trip Dixon used 20 gallons of gas you get this buy dividing 600 miles by 30 miles per gallon and you get 20 gallons hope this helps
1) 8^3/4 = 4th root (8^3) (top row, third one)
2) 7^2/3 = ∛7^2 (second row, third one)
3) 3^4/3 = ∛3^4 (second row, first one)
4) 25^3/4 = 4th root (25^3) (first row, first one)
5) 44^3/2 = √44^3 (third row, first one)
You need to have a height as well, because the formula for volume is length*width*height.