Problem: Log function with common base equation ln(x-2)-ln(x+9)=ln(x-1)-ln(x+14) I dropped the ln's and tried solving by using the quotient property but I think im doing the fractions wrong. can someone please explain how to get the answer? (solving for x) Thank you

firestopper53sh

firestopper53sh

Open question

2022-08-21

Problem: Log function with common base equation
ln(x-2)-ln(x+9)=ln(x-1)-ln(x+14)
I dropped the ln's and tried solving by using the quotient property but I think im doing the fractions wrong.
can someone please explain how to get the answer? (solving for x)
Thank you

Answer & Explanation

hrikalegt15

hrikalegt15

Beginner2022-08-22Added 11 answers

ln ( x 2 ) ln ( x + 9 ) = ln ( x 1 ) l n ( x + 14 ) ln ( x 2 x + 9 ) = ln ( x 1 x + 14 ) , but ln ( x ) is bijective and so
x 2 x + 9 = x 1 x + 14
and solving that we have:
( x 2 ) ( x + 14 ) = ( x 1 ) ( x + 9 ) x = 19 / 4
and testing that solution at the original equation we see that it holds.
ureq8

ureq8

Beginner2022-08-23Added 2 answers

I'm approaching this within the context of the natural log, until we have a clear equation with which to solve for x
ln ( x 2 ) ln ( x + 9 ) = ln ( x 1 ) ln ( x + 14 )
ln ( x 2 x + 9 ) = ln ( x 1 x + 14 )
ln ( x 2 x + 9 ) ln ( x 1 x + 14 ) = 0
ln ( x 2 x + 9 x 1 x + 14 ) = 0
ln ( ( x 2 ) ( x + 14 ) ( x 1 ) ( x + 9 ) ) = 0
Noting that ln ( f ( x ) ) = 0 f ( x ) = 1, we have f ( x ) = g ( x ) h ( x ) = 1, meaning we must have
(solve for x) ( x 2 ) ( x + 14 ) = ( x 1 ) ( x + 9 )
to arrive at ln ( 1 ) = 0

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?