# in-out table

#### csalas

##### New member
Trying to help my 7th grade son with this

2 10 6 7 -3 -8 -10 100
-4 4 0

Need to finish out the table with a formula that does not include -6. According to my son the teacher claims the formula starts with multiplication then subtraction.

Any thoughts?

2-6 = -4
10-6 = 4
6-6 = 0
OK?

#### soroban

##### Elite Member
Hello, csalas!

The problem is really stupid!
Why are the upper numbers in scrambled order?
How can we possibly find a pattern from that?

"Does not include -6" . . . Why?
Are we to look for another (more imaginative) function?

That could take a while . . .

Trying to help my 7th grade son with this

. . $$\displaystyle \begin{array}{|c|c|c|c|c|c|c|c|}\hline 2 & 10 & 6 & 7 & -3 & -8 & -10 & 100 \\ \hline -4 & 4 & 0 & & & & & \\ \hline \end{array}$$

Need to finish out the table with a formula that does not include -6.
According to my son, the teacher claims the formula starts with multiplication then subtraction. . How?

Here's a silly function that cranks out the first three values: .$$\displaystyle f(x) \;=\;x^3 - 18x^2 + 93x - 126$$

. . $$\displaystyle \begin{array}{cccc}\text{We have: } & f(2) &=& \text{-}4 \\ & f(10) &=& 4 \\ & f(6) &=& 0 \\ \\ \text{Then:} & f(7) &=& \text{-}602 \\ & f(\text{-}3) &=& \text{-}270 \\ & \vdots && \vdots \end{array}$$

I said it was silly, didn't I?

#### csalas

##### New member
Yah, understand the real silly part of this one. I'm helping my son from long distance for now. Until now he has been very good at passing on instructions, but this one just dosen't ring right. Got an email into his teacher