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Solve |x - 3| + 2 < 6

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

Step by step

The question

Question: solve |x − 3| + 2 < 6.

|x − 3| + 2 < 6

1 Get the bars alone

We want the bars by themselves.

The + 2 is in the way, so we take away 2 on both sides.

|x − 3| + 2 − 2 < 6 − 2

+ 2 and − 2 make zero.

Cross them out.

6 minus 2 is 4.

|x − 3| < 4

2 Draw the distance

3 Write it without bars

So x − 3 is between −4 and 4: −4 < x − 3 < 4.

Now x is in the middle.

−4 < x − 3 < 4

4 Remove the − 3

We want x by itself.

The − 3 is in the way.

To remove − 3, we add 3.

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.

−4 + 3 < x − 3 + 3 < 4 + 3

− 3 and + 3 make zero.

Cross them out.

−4 plus 3 is −1.

4 plus 3 is 7.

−4 + 3 = −1
4 + 3 = 7

Now we have −1 < x < 7.

So x is between −1 and 7: −1 < x < 7.

−1 < x < 7

5 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, 7)

6 Check

Let's test one number from the answer: 4.

We put it in the question.

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

x = 4: |4 − 3| + 2 = |1| + 2 = 1 + 2 = 3

3 is less than 6.

True!

So the answer works.

3 < 6

Let's look back.

First: get the bars alone.

Then: draw the distance.

Then: write it without bars.

Then: remove the − 3.

Then: show it on a number line.

Last: check.

Answer
−1 < x < 7

Your turn

Try this one yourself, then check:

Solve |x − 4| + 2 < 8
Show the answer
−2 < x < 10

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