Question

VALENDO 20 PONTOS!!!
Dada a matriz M = $\left[\begin{array}{ccc}1&0&2\\-1&3&4\\-2&-1&-7\end{array}\right]$, calcule o valor de det ( m )
POR FAVOR COM CÁLCULOS


a) - 39

b) 0

c) 13

d) -35

e) - 3

Answer 1

Use a Regra de Sarrus:

$\left|\begin{array}{ccc}1&0&2\\-1&3&4\\-2&-1&-7\end{array}\right|\begin{array}{ccc}1&0\\-1&3\\-2&-1\end{array}\right] \\\\\\det(m) = - 21 + 0 + 2 - (- 12 - 4 + 0)\\det(m) = - 19 + 16\\det(m) = - 3$

Resposta: e) - 3

Answer 2

Explicação passo-a-passo:

$\sf det~(M)=1\cdot3\cdot(-7)+0\cdot4\cdot(-2)+2\cdot(-1)\cdot(-1)-(-2)\cdot3\cdot2-(-1)\cdot4\cdot1-(-7)\cdot(-1)\cdot0$

$\sf det~(M)=-21-0+2+12+4-0$

$\sf det~(M)=18-21$

$\sf \red{det~(M)=-3}$

Letra E