Steply

Solve 6 < 2x

Step by step, with the reason for every step · Inequalities · Algebra 1

Step by step

The question

Question: solve 6 < 2x.

This is an inequality.

The sign means less than.

6 < 2x

Let's swap the two sides, so x is on the left.

When we swap, the sign turns around too.

Less than becomes greater than.

2x > 6

1 Remove the 2

2x means 2 times x.

We want just x.

To remove times 2, we divide by 2.

We do it on both sides.

Why both sides?

The sign compares the two sides.

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

2x2 > 62

2 divided by 2 is 1.

So just x is left.

6 divided by 2 is 3.

62 = 3

So x is greater than 3.

x > 3

2 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.

∞ means it goes on for ever.

interval: (3, ∞)

3 Check

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

We put it in place of x.

First the left side.

Left: 6

Now the right side.

Right: 2(4) = 8

6 is less than 8.

True!

So the answer works.

6 < 8

Let's look back.

First: remove the 2.

Then: show it on a number line.

Last: check.

Answer
x > 3

Your turn

Try this one yourself, then check:

Solve 10 < 5x
Show the answer
x > 2

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