Write an algebraic statement that represents all the ways your player will win? (Be sure to define your variable)

Erik and Nita are playing a game with numbers. In the game, they each think of a random number from zero to 20. If the difference between their two numbers is less than 10, then Erik wins. If the difference between their two numbers is greater than 10, then Nita wins. Nita chose 7 Erik chose 17