#### Answer

$\frac{2}{x-3}$

#### Work Step by Step

To simplify, divide both the numerator and denominator by their greatest common factor.
Use the distributive property to find the GCF.
$\frac{12}{6x-18}=\frac{12}{6(x-3)}=\frac{12\div6}{6(x-3)\div6}=\frac{2}{x-3}$