Which tables represent constant functions?

Step-by-step explanation:

A constant function refers to those functions that only have one variable, which is constant. For example, x=2, y=4, x=-1, are constant function, because they don't variate.

From the given tables, the third and last choices are constant function, because you can observe that one variable doesn't variate. The third function has y=3 as the constant value, and the last table has y=-1 is the constant function.

Therefore, the right choices are third and last table.