Question

look at this table:

x	y
9	-9
19	18
8	19
12	-1

is this relation a function?
yes
no

Explanation:

A relation is a function if every input (x-value) has exactly one corresponding output (y-value). Checking the table, each x-value (18, 9, 19, 8, 12) appears only once, meaning no x-value maps to more than one y-value.

Answer:

yes