Question

Dadas as matrizes: (foto)


Então, a soma dos elementos da primeira coluna de A · B será:

A
0

B
2

C
3

D
7

E
8

Answer 1

Resposta: 2

$\left[\begin{array}{ccc}1&2\\3&4\\\end{array}\right] .\left[\begin{array}{ccc}-1\\1\\\end{array}\right] =\left[\begin{array}{ccc}[1.(-1)+2.1\\3.(-1)+4.1\\\end{array}\right] = \left[\begin{array}{ccc}1\\1\end{array}\right]$