Solve -(x - 1) = 4 Step by Step

Step by step

The question

Question: solve −(x − 1) = 4.

−(x − 1) = 4

1 Open the brackets

A minus in front of a bracket changes the sign of every part inside.

x becomes −x.

−1 becomes +1.

−x + 1 = 4

2 Remove the + 1

We want x by itself.

The + 1 is in the way.

To remove + 1, we take away 1.

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.

−x ~~+ 1 − 1~~ = 4 − 1

+ 1 and − 1 make zero.

Cross them out.

4 − 1 = 3.

4 − 1 = 3

Now we have −x = 3.

−x = 3

3 Remove the −1

−x means −1 times x.

We want just x.

To remove times −1, we divide by −1.

We do it on both sides, so they stay equal.

−x−1 = 3−1

−1 divided by −1 is 1.

So just x is left.

3 divided by −1 is −3.

3−1 = −3

So x = −3!

x = −3

4 Check

Let's check: put −3 in place of x.

Check: −(−3 − 1) = −(−4) = 4

We get 4, the same as the right side.

So x = −3 is right!

Let's look back.

First: open the brackets.

Then: remove the + 1.

Then: remove the −1.

Last: check.

Answer