Question

which set of ordered pairs does not represent a function?
answer
\\(\\{(-6, -4), (-2, -4), (-4, -7), (7, -6)\\}\\)
\\(\\{(1, -9), (5, 2), (-9, 4), (5, -5)\\}\\)
\\(\\{(-1, 9), (-9, 3), (-8, 9), (-7, -2)\\}\\)
\\(\\{(9, -3), (8, 0), (-5, -3), (1, 2)\\}\\)

Explanation:

Step1: Recall function definition

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

Step2: Check set 1

All x-values: $-6, -2, -4, 7$ are unique.

Step3: Check set 2

x-value $5$ appears twice, paired with $2$ and $-5$.

Step4: Check set 3

All x-values: $-1, -9, -8, -7$ are unique.

Step5: Check set 4

All x-values: $9, 8, -5, 1$ are unique.

Answer:

$\{(1,-9),(5,2),(-9,4),(5,-5)\}$