Drink the water so you have none left
Okay. So first you subtract 2x from each side. That will give you 4y= -2x+18 (you want to get y by itself). Then you divide both sides by 4. It should equal> y= 1/2x +9/2
According to Wikipedia: "<span>In mathematics, a function
is a relation between a set of inputs and a set of permissible outputs
with the property that each input is related to exactly one output."
So based of this we need to look for a set where one of the x values or the y values is the same, and the other number is different.
Answer:
B.
(1,4) and (1,1) both have the same x, but different y!
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