Find the Solution of the Exponential Equation? How do I solve 5 x </msup> =

Thalia Ortiz

Thalia Ortiz

Answered question

2022-06-03

Find the Solution of the Exponential Equation?
How do I solve 5 x = 4 x + 1?
I understand how to solve for x when there is one exponent, but I don't know how to solve when there is an exponent on both sides of the equation..

Answer & Explanation

jillrozellmzoej

jillrozellmzoej

Beginner2022-06-04Added 3 answers

If a > 1
a x = e ln a x = e x ln a d a x d x = ln a a x > 0
Therefore a x is strictly increasing in R and it follows it is injective.
Now, Since 5 4 > 1, the exponential ( 5 4 ) x is strictly increasing in R , and consequently so is
( 5 4 ) x 1
Multiply by the strictly increasing 4 x to get an injective function:
[ ( 5 4 ) x 1 ] 4 x = 5 x 4 x
The conclusion is that there is at most one real x that satisfies 5 x 4 x = 1, which is equivalent to:
5 x = 4 x + 1
This single x is 1 as Tom Bombadil pointed out.

Do you have a similar question?

Recalculate according to your conditions!

Ask your question.
Get an expert answer.

Let our experts help you. Answer in as fast as 15 minutes.

Didn't find what you were looking for?