Solve 5 - 2x = 11

Step by step

The question

Question: solve 5 − 2x = 11.

We want x by itself.

Two things are stuck to x: times −2 and + 5.

The + 5 is on the outside, so it comes off first.

Then the times −2.

1 Remove the 5

To remove 5, we take away 5.

We do it on both sides.

Why both sides?

The = sign means both sides are the same amount.

If we change only one side, they are not the same any more.

5 and − 5 make zero.

Cross them out.

11 − 5 = 6.

Now we have −2x = 6.

2 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, so they stay equal.

−2 divided by −2 is 1.

So just x is left.

6 divided by −2 is −3.

So x = −3!

3 Check

Let's check: put −3 in place of x.

We get 11, the same as the right side.

So x = −3 is right!

Let's look back.

First: remove the 5.

Then: remove the −2.

Last: check.