Which set of ordered pairs does not represent a function?

Answer:
The first answer: {(-3, 9), (7,9), (9, 1), (7, 3)}.
Step-by-step explanation:
If any set of ordered pairs have at least two of the same x values(the first number in the coordinate), it is not a function.
Answer:
[tex]\{(-3,-9),(7,9),(9,1),(7,3)\}[/tex]
Step-by-step explanation:
A relation is a function only if each element of the domain is related exclusively to one element of the codomain. Then, the following set of ordered pairs is not a function:
[tex]\{(-3,-9),(7,9),(9,1),(7,3)\}[/tex]