1. ## LN

$2^{1-x}=3$
$LN2^{1-x}=LN3$
I am stuck. I have to use LN but it doesn't seem to work.

2. ## Re: LN

$\ln a^b = b\ln a$ does this help?

3. ## Re: LN

After that I have no idea what to do.
1-x(LN2)=LN3

-x(LN2)=LN3-1

x=LN3-1/-LN2

4. ## Re: LN

$\ln2^{1-x}=\ln3$

Becomes

$(1-x)\ln2=\ln3$

$1-x=\frac{\ln3}{\ln2}$