Question

Which set of ordered pairs is not a function?

A. (3, 1), (–1,1), (1, 1), (3, −1)
B. (–3, 1), (–1, 1), (1, 1), (3, 1)
C. (–3, 1), (–1, –1), (1, 1), (3, 1)
D. (–3, 1), (–1, –1), (1, 1), (3, −1)

Answer 1

A

Explanation:

Answer 2

A.

It isn't a function because if you look at the inputs (x-coordinates) there are two 3 in the x place