For this question, we have an equation in two unknowns. This means that, if we're given the value of one, we can (in this example) easily solve for the other. Let's pick values for x, then, and see what those force y to be.
When x = 3:
3 - y = 3
The only number that would work for y here is 0, so our ordered pair for x = 3 is (3, 0).
When x = 4:
4 - y = 3
and y = 1, giving us (4, 1)
When x = 5, 5 - y = 3 and y = 2, giving us (5, 2)
And when x = 6, 6 - y = 3 and y = 3, giving us (6, 3)
Four ordered pairs that make this equation true then are (3, 0), (4, 1), (5, 2), and (6, 3)