Question

look at this set of ordered pairs:
(0, 0)
(-18, 0)
(6, 17)
(12, -19)
is this relation a function?
yes no

Explanation:

Step1: Recall function definition

A relation is a function if each input (x - value) has exactly one output (y - value).

Step2: Check x - values

Check the x - values of the ordered pairs: 0, - 18, 6, 12.
Each x - value appears only once. So each input has exactly one output.

Answer:

yes