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Linear or not: x 1, 2, 3, 4; y 3, 6, 12, 24

Step by step, with the reason for every step · Linear or not · Algebra 1

Step by step

The question

Question: is this table linear: x is 1, 2, 3, 4, and y is 3, 6, 12, 24?

x: 1, 2, 3, 4; y: 3, 6, 12, 24

Linear means: a straight line.

y changes by the same amount every time x goes up by 1.

linear = y changes by the same amount
for each 1 of x

We write it as a table.

1 Check the changes

From one y to the next: plus 3, then plus 6, then plus 12.

The changes are not the same.

So it is not linear.

= not the same → not linear

Careful!

Going up every time is not enough.

A line changes by the same amount every time.

Careful: it goes up every time, but by different amounts

2 Check

Let's check: the changes for each 1 of x are 3, 6, 12.

Not all the same.

So the answer is right!

3, 6, 12: not the same

Let's look back.

First: check the changes.

Last: check.

Answer
Careful: it goes up every time, but by different amounts

Your turn

Try this one yourself, then check:

Is this table linear: x: 1, 2, 3, 4; y: 7, 13, 23, 37
Show the answer
not linear

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