Question

Qual o determinante da Matriz Quadrada abaixo, aplicando-do a Regra de Sarrus. *
3 pontos
1 2 5
-2 1 3
-1 3 -2
Imagem sem legenda
A) - 38 - 10 = - 48
B) 38 - (-12) = 50
C) - 38 - 12 = - 50
D) 38 - (-10) = 48
E) 38 - 12 = 26

Answer 1

$\small\boxed{\begin{array}{l}\sf A=\begin{bmatrix}\sf1&\sf2&\sf5\\\sf-2&\sf1&\sf3\\\sf-1&\sf3&\sf-2\end{bmatrix}\begin{bmatrix}\sf1&\sf2\\\sf-2&\sf1\\\sf-1&\sf3\end{bmatrix}\\\sf det~A= 1\cdot1\cdot(-2)+2\cdot3\cdot(-1)+5\cdot(-2)\cdot3\\\sf-2\cdot(-2)\cdot(-2)-1\cdot3\cdot3-5\cdot1\cdot(-1)\\\sf det~A=-2-6-30-8-9+5\\\sf det~A=-50\end{array}}$