Question

The answer choices are:
-17
-8
-2
2
5
8
15

Answer 1

-8, 2, 15

Explanation:

For a function each input value can have one and only one output value

Therefor -17, -2, 5, 8 cannot be input values because they already have output values other than 9

Valid inputs are

-8, 2, 15