solve equation for x:
12^(x - 7) = 7
can someone please help me with this?
Hi darkblue,
This is what he means.
Take the natural log of both sides and use this:
$\displaystyle \ln a^r=r \ln a$,
$\displaystyle 12^{x-7}=7$
$\displaystyle \ln 12^{x-7}=\ln 7$
$\displaystyle (x-7)\ln 12=\ln 7$
$\displaystyle x-7=\frac{\ln 7}{\ln 12}$
$\displaystyle x=\frac{\ln 7}{\ln 12}+7$