SOLUTION: Function Table In Out 2 .6 4 2.2 5 3 What is the rule? (In =x and out = answer)

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Question 156414: Function Table
In Out
2 .6
4 2.2
5 3
What is the rule?
(In =x and out = answer)
Answer by solver91311(24713) About Me  (Show Source):
You can put this solution on YOUR website!
Use the two-point form of a straight line against two of the points and then test the other point against the rule you develop to see if the three given points are colinear.

y-y%5B1%5D=%28%28y%5B1%5D-y%5B2%5D%29%2F%28x%5B1%5D-x%5B2%5D%29%29%28x-x%5B1%5D%29

Let P%5B1%5D be (5,3) and P%5B2%5D be (4,2.2)

So y-3=%28%283-2.2%29%2F%285-4%29%29%28x-5%29

y-3=0.8%28x-5%29

y-3=0.8x-4

y=0.8x-1 is your rule. Now check the other point:

Does 0.6=0.8%282%29-1? 0.6=1.6-1, 0.6=0.6 -- Yep.

So your rule fits all three points and you are good to go.