SOLUTION: input x: 1,2,4,5,6,8,9 outputy: 7,9,13,?,?,? I cant find a correct expression for this prob.

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Question 652962: input x: 1,2,4,5,6,8,9
outputy: 7,9,13,?,?,?
I cant find a correct expression for this prob.
Answer by solver91311(24713) (Show Source):
You can put this solution on YOUR website!

The first thing to do is to see if the relationship is linear. Use the slope formula and any two pairs of the first three (x, y) ordered pairs.

where and are the coordinates of the given points.

Same slope, so the points are collinear, so the function is linear.

Since it is a linear function the function can be written in the form

Substitute values:

Since we already know the slope:

So

Now all you need to do is substitute the values of x for which you have no y value and do the arithmetic.

John

My calculator said it, I believe it, that settles it