Question

AJUDA ???

1- Determine o valor da expressao :

.

  2  .   3 -1         4 2 1
           2 3     .    0 3 2
                           2 2 1 

Answer 1

Olá, Jacque.

 

$<var> |2|=2 \\\\\\ \begin{vmatrix}3& -1 \\ 2 & 3 \end{vmatrix}=3\cdot3-2\cdot(-1)=9+3=12 \\\\\\ \begin{vmatrix} 4 &2& 1 \\ 0 &3& 2 \\ 2 &2& 1 \\ \end{vmatrix}= \begin{vmatrix} 4 &2& 1 \\ 0 &3& 2 \\ 2 &2& 1 \\ \end{vmatrix} \begin{vmatrix} 4 &2 \\ 0 &3 \\ 2 &2 \\ \end{vmatrix}=\underbrace{(12+8+0)}_{=20}-\underbrace{(6+16+0)}_{=22}=-2 </var>$

 

 

$<var>\therefore |2| \cdot \begin{vmatrix}3& -1 \\ 2 & 3 \end{vmatrix} \cdot \begin{vmatrix} 4 &2& 1 \\ 0 &3& 2 \\ 2 &2& 1 \\ \end{vmatrix}=2 \cdot 12 \cdot (-2) = \boxed{-48}</var>$