Question

I need help!
Is the relationship shown by the data linear? If so, model the data with an equation.
x | y
-7 5
-5 9
-3 13
-1 17

Answer 1

try this -7/5 = -7/5
and -5 /9 = -5/9
is =-5/9=-7/5 ?
if that's not true the variation is indirect.

Answer 2

You can tell it is not a direct variation right?

Answer 3

right..

Answer 4

Good!

Answer 5

so is it the relationship is not linear.

Answer 6

?

Answer 7

What do you think?

Answer 8

i think it might be that. but i dont want to get it wrong..

Answer 9

Well, you can see that it's not "linear" if you know what that means, and you do...

Answer 10

hmmm..

Answer 11

@SolomonZelman
May I ask if linear relationship the same as direct variation?

Answer 12

To my understanding, direct variation (y ∝ x) means that y = kx, where k is a constant.
However, for linear relationship, it can be represented in a linear equation, that is y=mx+c, where m and c are constants.

In this case, even if their ratios are not the same, it does not imply that they are not in a linear relationship.

If the definition I have is correct, one of the way to solve this problem may be as follows:
1) Establish the equation y = mx + c
2) Plug two sets of data into the equation to solve m and c, which are constants
3) Plug x in the 3rd and 4th pair of data into mx+c (in this step, you should know the value of m and c), and see if it equals to the value of their y's.
If they equals to their y's, then they have a linearly relationship, and vice versa.

Answer 13

was he wrong?

Answer 14

Have you solved it?