Question

look at this table:
x | y
3 | 2
8 | -1
-7 | 2
is this relation a function?
yes no

Explanation:

Step1: Recall function definition

A relation is a function if every input ($x$-value) has exactly one output ($y$-value).

Step2: Check $x$-values in table

The $x$-values are 3, 8, -7. Each $x$-value appears only once, so each has exactly one corresponding $y$-value.

Answer:

yes