SOLUTION: I need help with a linear function table. Here's the table: x f(x) -6 -15 1 -1 7 11 11 19 I tried to find the pattern for the y's and the x'

Question 30514: I need help with a linear function table. Here's the table:
x f(x)
-6 -15
1 -1
7 11
11 19
I tried to find the pattern for the y's and the x's so that I could find the slope, but it doesn't seem like there is a pattern. I need to write the rule for the linear equation. Can you help?
Thanks
Answer by longjonsilver(2297) (Show Source): You can put this solution on YOUR website!
you say it is a linear function, so in that case, we are looking for a "times table".

Pick any 2 values of x... say 7 and 11. They differ by 4. Their F(x) values are 11 and 19, which differ by 8.

So, x increases by 4 whilst y increases by 8... looks like the 2 times table to me.

--> f(x) = 2x

Now, it isn't THE 2x table: 2,4,6,8,10,... etc, but it is this shifted.

So, when x=7, f(x)=2x gives f(x)=14. Our function actually gives 11, so we need to subtract 3: f(x)= 2x-3.

CHECK:
when x=-6
f(-6) = 2(-6) - 3
f(-6) = -12 - 3
f(-6) = -15... CORRECT

You can then tell what the slope of the line is from y=2x-3

jon.
RELATED QUESTIONS
The table shows values for a linear function, f(x). x f(x) -1 -8 3 -5 7 (answered by Boreal)

I dont know exactly what topic this is in but i need to write a rule for a function... (answered by solver91311)

There is an x and y table. I need help on finding the pattern/equation/expression so I... (answered by stanbon)

Directions: Determine whether each is a linear function or not. Check Yes if it is a... (answered by Solver92311,josgarithmetic,greenestamps)

Please help me solve this problem. There's a table, and it looks kind of like this: x (answered by solver91311,scott8148)

I only need help with this question because its getting me mad. Question: write a... (answered by ewatrrr)

State a function rule that matches the input-output table? x|y 1|7 2|11 3|15 4|19 (answered by stanbon)

I have a table with x values and f(x)values for which I am trying to determine a pattern... (answered by josgarithmetic,stanbon)

MAT 145: Topics In Contemporary Math QUESTION 12 Convert the message (answered by ikleyn)