Solve -x = 7

Step by step

The question

Question: solve −x = 7.

1 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.

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.

−1 divided by −1 is 1.

So just x is left.

7 divided by −1 is −7.

So x = −7!

2 Check

Let's check: put −7 in place of x.

We get 7, the same as the right side.

So x = −7 is right!

Let's look back.

First: remove the −1.

Last: check.