Answer:
The first 2 on top is not a function. The 3rd one on top and the bottom 2 are functions.
Explanation:
The x-value cannot have more than 1 y-value or else when you plot the points on the graph, it doesn't meet the vertical line test. The vertical line test indicates whether or not the graph is a function. Different x-values can have the same y-value.
Function examples: (3,-4), (5,0), (0,-4), (1,2)
Not a Function examples: (0,8), (2,-1), (0,-2), (-5,3)