In a function, every input has one and only one output.
if -5 is your input, then 5 is the output
if 8 is your input, then 0 is your output
multiple inputs can lead to the same output, like
-6 as the input can give an output of 7
and also -7 as the input can give an output of 7
however, multiple one input cant not have multiple outputs.
since none of those values share the same x values with different y values, the relation is in fact a function.
the answer should be true