John flies from Atlanta, Georgia to San Francisco, California. It takes 5.6 hours to travel 2100 miles against the head wind. At the same time, Debby flies from San Francisco to Atlanta. Her plane travels with the same average airspeed, but with a tail wind, and her flight takes only 4.8 hours. Write a system of equations that relates time, airspeed, and wind speed to distance for each traveler. Solve the system to find the airspeed.