Question

look at this table:

x	y
20	15
0	4
10	1

is this relation a function?

yes
no

Explanation:

Step1: Recall function definition

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

Step2: Check x - values

Check the x - values in the table: 5, 20, 0, 10. Each x - value appears only once, so each input has exactly one output.

Answer:

yes