#### Answer

$\dfrac{3x-12}{x^{2}-4x}=\dfrac{3}{x}$

#### Work Step by Step

$\dfrac{3x-12}{x^{2}-4x}$
Take out common factor $3$ from the numerator and common factor $x$ from the denominator and simplify:
$\dfrac{3x-12}{x^{2}-4x}=\dfrac{3(x-4)}{x(x-4)}=\dfrac{3}{x}$