Prove that this relationship is true (image attached)

From the picture, we can see that

which means

part 1 answer = 8

part 2 answer = 72

step-by-step explanation:

part 1 explanation = add all of the numbers, then divide by how many numbers you have. so, 200/25 = 8.

part 2 explanation = not gonna lie, this is hard to explain, so just google how to do it.

yes because there is exactly one y value for every x value

for function there can't be more than one value for every x value