Which of these relations are functions?

x 2 -2 6 2 -6
y 11 -5 21 15 -15

x 4 -4 7 -7 -4
y 3 -2 11 5 -5

{(-5,-7), (-2,-7), (7,17), (-5,21)}

 None of them are functions.

Step-by-step explanation:

By definition, a relation is a function  if and only if each input value have an unique output value.

You need to remember that the input values are the x-values and the output values are the y-values.

In the first table you can observe that the input value 2 has two different output values:

Therefore, this relation is not a function.

Notice that in the second table the input value -4 has two different output values:

Therefore, this relation is not a function.

In the set , observe that the input value -5 has two different output values:

Therefore, this relation is not a function.

whatever you can spend with $11.53 or under.

step-by-step explanation:

20 - 8.47 = 11.53. take away the money he used for lunch from the starting amount of 20.