In an ordered pair, x is the first number and y is the second number. So this is telling you x=1 and y=-5. You can take this information and plug it into the formulas.
x + 2y = -9
1 + 2(-5) = -9
1 + -10 = -9? True
x - y = 6
1 - -5 = 6? *
1 + 5 = 6? True.
(*Subtracting a negative makes it a positive.)
