Which set of ordered pairs represents a function?
{(0, 1), (1, 3), (1, 5), (2, 8)}
{(0, 0), (1, 2), (2, 6), (2, 8)}
{(0, 0), (0, 2), (2, 0), (2, 4)}
{(0, 2), (1, 4), (2, 6), (3, 6)}
explain why.

The very last set
{(0, 2), (1, 4), (2, 6), (3, 6)}.

The reason why is because of the vertical line test. If there are two y-coordinates on a x-coordinate then it is not a function. A function is that each x-coordinate has a y-coordinate with the x-coordinates being different.

Example is above. If you have any questions then leave a comment. Good luck!