Hello, jhon!

You're expected to know the basic rules of logs and exponentials.

Here's the last part . . .

Take logs of both sides: .Solve for .

Then: .

Since , we have: .

Therefore: .

Take logs of both sides: .

Then: .

Expand: .

Rearrange: .

Factor: .

Therefore: .

The last three can be solvedwithout logs. . .

We have: .

Therefore: .

We have: .

Therefore: .

We have: .

Therefore: .