Arithmetic

[Joseph]

Hello.

I have another question.

I need to write a rule for the function represented by each table.

x y
1 4
2 8
3 12
4 16 I did this one myself.

my answer is y = x (4)

Here is one I got stuck on....

x y
1 -6
2 -9
3 -12
4 -15 Can you please help me out with this one.

 

[tkhunny]

One question per topic, please.

Can you see a pattern? That is where you should start.

 

[Deleted member 4993]

Hello.

I have another question.

I need to write a rule for the function represented by each table.

x y
1 4
2 8
3 12
4 16 I did this one myself.

my answer is y = x (4)

Here is one I got stuck on....

   x     y
   1     -6    

   2     -9       -6 + (-3)*1

   3     -12      -6 + (-3)*2
 
   4     -15      -6 + (-3)*3

Can you please help me out with this one.

 

[soroban]

Hello, Joseph!

Write a rule for the function represented by each table.

. . \(\displaystyle \begin{array}{cc} x & y \\ \hline 1 & 4 \\ 2 & 8 \\ 3 & 12 \\ 4 & 16\end{array}\)

I did this one myself.

My answer is: .\(\displaystyle y \,=\, 4x\)

This is correct, but how did you get it?

I suppose you just guessed the answer.

If you used any reasoning, you could get the second problem.

Here is one I got stuck on:

. . \(\displaystyle \begin{array}{cc} x & y \\ \hline 1 & \text{-}6 \\ 2 &\text{-}9 \\ 3 & \text{-}12 \\ 4 & \text{-}15 \end{array}\)

Look at what we have:

. . \(\displaystyle \begin{array}{cc} x & y \\ \hline {\bf1} & \text{-}3({\bf2}) \\ {\bf2} & \text{-}3({\bf3}) \\ {\bf3} & \text{-}3({\bf4}) \\ {\bf4} & \text{-}3({\bf5}) \end{array}\)

\(\displaystyle \text{We see that: }\;y\,\text{ is equal to }\,\text{(negative 3) times (one more than }x)\)

\(\displaystyle \text{Therefore: }\;y \:=\:-3(x+1)\)

 

[Joseph]

Thank you.

This was very helpful.