When you are trying to figure this out put them into a list vertically. Remember, ONE X CAN'T HAVE TO Y's BUT ONE Y CAN HAVE MULTIPLE X's, But dont worry about the y's right now. Lets focus on the x's.
Ask yourself, Are there 2 or more x's that are the same value? Yes) Continue to next step No) It's a function :)
If there are 2 or more of the same x value, ask your self now if those x's have different y Values. Yes) It is not a function, one x can not have more that 1 y value No) Its a function :)
