Solve 2^x + 9 = 1

Step by step

The question

Question: solve 2 to the power x, + 9 = 1.

x is up in the power.

1 Get the power alone

First the power must be alone: nothing added to it, nothing times it.

We want the power by itself.

The + 9 is in the way.

To remove + 9, we take away 9.

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.

+ 9 and − 9 make zero.

Cross them out.

1 − 9 is −8.

Now we have 2ˣ = −8.

2 Look at the sign

2 is positive.

A positive number to any power is positive.

It is never negative.

So it can never be −8.

There is no solution.

Let's look back.

First: get the power alone.

Last: look at the sign.