$$\log \frac { x y } { z } + \log \frac { z } { x }$$
$\log(e)\left(\ln(\frac{xy}{z})+\ln(\frac{z}{x})\right)$
$\log_{10}\left(e\right)\left(\ln(\frac{xy}{z})+\ln(\frac{z}{x})\right)$
