Answer: All of the them except for the last relation.
Step-by-step explanation: For a relation to be a function, it can have y-values repeat but not x-values. In the last relation, you have (6,-6,), (-3,12), (6,-1), (-8,13). Notice that the x-value of 6 repeats 2 times in this relation. You can graph this relation and use the vertical line test and you will notice that it will touch the graph more than one time. Therefore, relations 1-4 represents functions and relation 5 does not.
Hope this explanation helps.
