help with this please

Step-by-step explanation:
I cannot do this table nicely here, but it is totally simple : the first number in brackets is the input, the second number the corresponding output.
you can do this easily and faster than in here.
it is not a function, because e.g. the input values -2 and 4 have more than 1 output value assigned (in different offered pairs, sure, but the whole group of ordered pairs defines the relationship).
-2 has 6 and 8
4 has 6 and 15
to be a function, each input value can have only one associated output value.