-3 and 2 should work
-17, 5, 8 will not work since they are already in the table and we know that the output will not be 9
about -8 and 15, I am not sure if they will work or not, but I think they will not
This is the first problem that I am so confused about, they probably want you to determine the function that is being used but that is really hard to do with only inputs and outputs.