SOLUTION: solve 2ln(x+1)=ln(x^2-1)+ln5

Click here to see ALL problems on logarithm

Question 975203: solve 2ln(x+1)=ln(x^2-1)+ln5
Found 3 solutions by Alan3354, solver91311, stanbon:
Answer by Alan3354(69443)   (Show Source):
You can put this solution on YOUR website!
solve 2ln(x+1)=ln(x^2-1)+ln5
----------------
ln(x+1)^2 = ln(5*(x^2-1))

Can you finish?

Answer by solver91311(24713)   (Show Source):
You can put this solution on YOUR website!

But

Hence

You can take it from here, I should imagine.

Don't forget to make sure that and are actually in the domain of the log function before you publish your solution.

John

My calculator said it, I believe it, that settles it

Answer by stanbon(75887)   (Show Source):
You can put this solution on YOUR website!
solve 2ln(x+1)=ln(x^2-1)+ln5
--------------
ln(x+1)^2 = ln[5(x^2-1)]
-----------------
(x+1)^2 = 5x^2 - 5
-------
x^2 + 2x + 1 = 5x^2 - 5
4x^2 - 2x - 6 = 0
------
2x^2 - x - 3 = 0
-----
Factor:
(2x-3)(x+1) = 0
----
Positive solution:
x = 3/2
-------
Cheers,
Stan H.
--------