Place the x values (if there are two of the same x value you only include it once) in the first box vertically like:
5
-3
6
2
Place the y values (if there are two of the same y values only include it once) in the 2nd box vertically like:
1.2
7
-3
Now draw lines from your x values to their corresponding y values.
A function may NOT have two y-values assigned to the same x-value, but it may have two x-values assigned to the same y-value.
So this is a function!