Question

ajuda com detsrminante de matrizes ?

Answer 1

1) $A=\left[\begin{array}{cc}3&-4 \\ 5&12\end{array}\right]$


$\text{Det}_{A}=3\cdot12-5\cdot(-4)=36+20=56$

Letra A

2) $B=\left[\begin{array}{ccc}2&4&9 \\ 0&0&0 \\ 1&2&-3\end{array}\right]$


$\text{Det}_B=2\cdot0\cdot(-3)+0\cdot2\cdot9+1\cdot4\cdot0-0\cdot4\cdot(-3)-2\cdot2\cdot0-1\cdot0\cdot0=0$

Letra A

3) $C=\left[\begin{array}{ccc}1&3&-4 \\ 5&6&0 \\ 6&9&-4\end{array}\right]$


$\text{Det}_C=1\cdot6\cdoot(-4)+5\cdot9\cdot(-4)+6\cdot3\cdot0-5\cdot3\cdot(-4)-1\cdot9\cdot0-6\cdot6\cdot(-4)$

$\text{Det}_C=-24-180+0+60-0+144=0$.

Letra C