algebra
posted by Kirstin .
The average gas consuption of Angels SUV is 21 miles per gallon. Jeffs car takes 20% less gas to drive the same distance. If Angel and Jeff drove from Sacramento to Phoenix a distance of 570 miles, how many gallons of gas would each need?

Jeffs car takes 20% less gas, so it gets 21/(10.2) miles per gallon.
To drive 570 miles at 21 miles per gallon requires 570/21 gallons.