The function and why it’s a function

Answer:
Its Table 3
Step-by-step explanation:
In a function each x value maps only to one y value.
So the first table is not a function because x=3 maps to 4 different values of y.
Similarly in Table 2, 0 maps to 7 and to -10 so its not a function.
Table 3 is a function because each value of x maps to just one value of y.