$$A = \left[ \begin{array}{rrr} -4 & -16 & -47\\ 1 & 9 & 32\\ 3 & 12 & 36 \end{array} \right]$$

(a) Compute $\det(A) =$

(b) Use Cramer's rule to solve the following system

$$\left\lbrace \begin{array}{rrrrrrrr}& -4 \, x_1&- &16 \,x_2&- &47 \,x_3&=&-1\\& \,x_1&+& 9 \, x_2&+& 32 \, x_3&=&1\\& 3 \,x_1&+& 12 \, x_2&+& 36 \, x_3&=&-1\\ \end{array} \right.$$

$x_1=$
$x_2=$
$x_3=$