Solve 2x + 3 = 11

Step by step

The question

Question: solve 2x + 3 = 11.

We want x by itself.

Two things are stuck to x: times 2 and + 3.

The + 3 is on the outside, so it comes off first.

Then the times 2.

1 Remove the + 3

To remove + 3, we take away 3.

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.

+ 3 and − 3 make zero.

Cross them out.

11 − 3 = 8.

Now we have 2x = 8.

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.

8 divided by 2 is 4.

So x = 4!

3 Check

Let's check: put 4 in place of x.

We get 11, the same as the right side.

So x = 4 is right!

Let's look back.

First: remove the + 3.

Then: remove the 2.

Last: check.