Answer:
1 and 2 are functions, 3 is not a function.
Explanation:
One x-value can lead to one y-value. If the x-value leads to more than one y-value like #3, then the relation is not a function.
If each input value leads to only one output value, classify the relationship as a function. If any input value leads to two or more outputs, do not classify the relationship as a function.