Question

Which of the sets of ordered pairs represents a function?

A = {(2, −2), (5, −5), (−2, 2), (−5, 5)}
B = {(4, 2), (4, −2), (9, 3), (9, −3)}

Answer 1

For something to be a function, the input (x value) can ONLY HAVE ONE output (y value), so if x has multiple outputs, it is not a function

B is not a function because x = 2 and x = 9 has 2 outputs

Your answer is A

Answer 2

Explanation:

A represents a function. Why? Because all the x-values are unique (no duplications).

B does not represent a function. Why? Because the input 4 is repeated and has different y-values for this one input, and similarly the input 9 is repeated.