Answer:
Function: A, C, F, H,I
NOT: B,D,E,G
Explanation:
To be a function every x is only allowed to pair up with one y. If there's no repeated x's, then its a function. If x repeats, it has to have the same y as the first time it showed up. If a vertical line (up and down) touches a graph in more than one place, its NOT a function. Any y can partner up with however many x's it wants to, doesn't matter, its still a function. But to be a function ONLY ONE y for each x. Life's not fair.