Steply

Solve |x - 2| < 3

Step by step, with the reason for every step · Absolute value inequalities · Algebra 1

Step by step

The question

Question: solve |x − 2| < 3.

|x − 2| < 3

1 Draw the distance

2 Write it without bars

So x − 2 is between −3 and 3: −3 < x − 2 < 3.

Now x is in the middle.

−3 < x − 2 < 3

3 Remove the − 2

We want x by itself.

The − 2 is in the way.

To remove − 2, we add 2.

We do it to all three parts.

Why all three?

The signs compare the three parts.

If we change only one part, the answer can change.

−3 + 2 < x − 2 + 2 < 3 + 2

− 2 and + 2 make zero.

Cross them out.

−3 plus 2 is −1.

3 plus 2 is 5.

−3 + 2 = −1
3 + 2 = 5

Now we have −1 < x < 5.

So x is between −1 and 5: −1 < x < 5.

−1 < x < 5

4 Show it on a number line

Books also write the answer like this.

It is called interval notation.

A round bracket means the end is not in, like the open circle.

interval: (−1, 5)

5 Check

Let's test one number from the answer: 3.

We put it in the question.

The inside is 1, and the bars make it 1.

x = 3: |3 − 2| = |1| = 1

1 is less than 3.

True!

So the answer works.

1 < 3

Let's look back.

First: draw the distance.

Then: write it without bars.

Then: remove the − 2.

Then: show it on a number line.

Last: check.

Answer
−1 < x < 5

Your turn

Try this one yourself, then check:

Solve |x − 4| < 5
Show the answer
−1 < x < 9

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