When using partial fractions to find antiderivatives in calculus we decompose complicated rational expressions into the sum of simpler expressions that can be integrated individually. The required decomposition is

$$\frac{3 x - 18}{(x - 6)(x + 6)} = \frac{A}{x - 6} + \frac{B}{x + 6}$$

Find the values of the missing constants.

$A =$
$B =$