# Help: (X+1)/(X-1)

• Jan 30th 2009, 05:12 AM
thomas33
Help: (X+1)/(X-1)
Hi,
Im having some problems solving following equation:
2^(X+1) = 3^(X-1) -> log 3/log 2 = (X+1)/(X-1).. but i cant get any further, please help.
How do i continue with (X+1)/(X-1) ? my guess is to get (X-1) to a number without X?
thanks
//Thomas
• Jan 30th 2009, 06:13 AM
masters
Quote:

Originally Posted by thomas33
Hi,
Im having some problems solving following equation:
2^(X+1) = 3^(X-1) -> log 3/log 2 = (X+1)/(X-1).. but i cant get any further, please help.
How do i continue with (X+1)/(X-1) ? my guess is to get (X-1) to a number without X?
thanks
//Thomas

Hi thomas,

$2^{x+1}=3^{x-1}$

$\log2^{x+1}=\log3^{x-1}$

$(x+1)\log2=(x-1)\log3$

You should be able to approximate x by finding log 2 and log 3 and solving the equation.
• Jan 30th 2009, 06:36 AM
thomas33
Quote:

Originally Posted by masters
Hi thomas,

$2^{x+1}=3^{x-1}$

$\log2^{x+1}=\log3^{x-1}$

$(x+1)\log2=(x-1)\log3$

You should be able to approximate x by finding log 2 and log 3 and solving the equation.

Thank you for the quick response: so say we find log2=0,301... and log3=0,477... , and tries to go further.

0,301(X + 1) = 0,477(X - 1) -> (0,477 - 0,301)X = 0,301 + 0,477 ->

0,176X = 0,778 -> X = 4,420 - does that sound correctly?

i tried to make log3/log2 before to get better result but ended up with the situationen as stated before! but, cant i somehow simplify the (x+1)/(x-1)?

//Thomas