I need help figuring out if this is a function or not and why

4) is a function 5) is not a function

Step-by-step explanation:

4) This is a function because even tho some numbers in the domain have the same y value that doesnt mean the x values overlap. THink of it graphically or draw points do the points overlap? It shouldn't unlike question 5!

5) This is NOT a function. Why??? This is because now all numbers except 4 have more than one y value for one x value

for example: 1 has -1 and 3

That would overlap!!