The equation has two variables x and y. For each value of x or y we will get a corresponding value of the other variable.
x - 2y = -8.
When x = 2, plug in value of x in the equation and we get
-2 - 2y = -8 that on simplification gives - 2y = -6 or y = 3
so the ordered pair is ( -2, 3 )
Similarly for the other ordered pair plug in the value of y to get corresponding value of x.