Answer
$\displaystyle \frac{3|x-2|}{x-2}$
Work Step by Step
With $u(x)=3x-6$,
$\displaystyle \frac{du}{dx}=3,$
apply the Generalized Power Rule (see table on p.823)
$\displaystyle \frac{d}{dx}|u|=\frac{|u|}{u}\frac{du}{dx}$
$\displaystyle \frac{d}{dx}|3x-6|=\frac{|3x-6|}{3x-6}\cdot 3$
$=\displaystyle \frac{3|3x-6|}{3x-6}=\frac{3\cdot|3||x-2|}{3(x-2)}=\frac{3|x-2|}{x-2}$
