Question

Which set of ordered pairs represents y as a function of x?

{(2,-1), (4, -2), (6, -3), (8, -4)}
{(0, 0), (1, 1), (1, 0), (2, 0)}
{(3, 3), (3, 4), (4, 3), (4, 4)}
{(1, -5), (1, 5), (2, -10), (2, -15)}

Answer 1

{(2,-1), (4, -2), (6, -3), (8, -4)}

Explanation:

The other ordered pairs have a common domain value which means they are not a function.

For example:

{(5,7), (5,8), (10,3)} would not be a function because the 5 is repeating

However

{(2,6), (4,6), (22,7)} would be function because there are no numbers in the x part of the ordered pair that repeat. (x,y)

I hope you can see the pattern now