Question

Encontre a matriz X= 2A–4B, sabendo-se que
A= [6 2]
[-7 -5]
e
B= [-3 8]
[-1 4]
A matriz X é:

a) X= [0 -28]
[-18 26]

b) X= [24 36]
[-10 -6]

c) X= [0 -36]
[18 6]

d) X= [24 -28]
[-10 -26]

e) X= [24 28]
[10 -26]
​

Answer 1

Resposta:

É a alínea d)

Explicação passo-a-passo:

$X=2A-4B$

$X=2\left[\begin{array}{ccc}6&2\\-7&-5\end{array}\right] -4\left[\begin{array}{ccc}-3&8\\-1&4\end{array}\right]$

$X=\left[\begin{array}{ccc}12&4\\-14&-10\end{array}\right] +\left[\begin{array}{ccc}12&-32\\4&-16\end{array}\right]$

$X=\left[\begin{array}{ccc}24&-28\\-10&-26\end{array}\right]$

A matriz X e igual a: $\left[\begin{array}{ccc}24&-28\\-10&-26\end{array}\right]$