Furthest to the left is a Hexagon. Middle is an Octagon. Furthest to the right is a Decagon.
A relation is a function if each element of the domain is paired with exactly one element of the range. ... If given a table, or a set of ordered pairs, you can look to see if any value of the domain has more than one corresponding value in the range.
tbh google
I believe that x=4 would be the answer