A company produces fruity drinks that contain a percentage of real fruit juice. Drink A contains 25% real fruit juice and Drink B contains 20% real fruit juice. Company made 280 liters of fruity drinks with 61 liters of real fruit juice. Write a system of equations that could be used to determine the number of liters of Drink A made and the number of liters of Drink B made. Define the variables that you use to write the system.