Question

Considere as matrizes A =
2 2
0 1
2 1


e B=
1 2 1
0 1 2

valor de Det (AB) é:
a) -6
b) -4
c) 0
d) 4
e)1

Answer 1

A*B

$\left[\begin{array}{ccc}2*1+2*0&2*2+2*1&2*1+2*2\\0*1+1*0&0*2+1*1&0*1+1*2\\2*1+1*0&2*2+1*1&2*1+1*2\end{array}\right] \\ \\ \left[\begin{array}{ccc}2&6&6\\0&1&2\\2&5&4\end{array}\right]$

det(AB)

2*(1*4-2*5) - 6*(0-4) +6*(0-2)
-12 + 24 - 12 = 0