The ordered pair (3, –1) is a solution of which system?

In your equation, put 3 where x is, and -1 where y is. If you get a true statement, like -8 = -8, or 69 = 69, then (3, -1) is a solution. If you get a false statement, like 9 = 21 or 10 = 420, then (3, -1) is not a solution.