Answer:
In general for a point we have (in, out)
The domain is the set of all the 'in's and the range is the set of all the 'out's
Domain: {2, 8, 1, 7} or {1, 2, 7, 8} in order
Range: {5, 3, 9} or {3, 5, 9}
Sets do not contain duplicates so 5 appears only once.