Question

Na resolução da equação matricial o valor de x + y + z é:
$\left[\begin{array}{ccc}1&-1&0\\4&-1&1\\0&-3&0\end{array}\right]$ . $\left[\begin{array}{ccc}x\\y\\z\end{array}\right] = \left[\begin{array}{ccc}1\\2\\0\end{array}\right]$

A) -2
B) 1
C) -1
D) 0

Answer 1

x-y = 1
4x-y+z = 2
-3y = 0 --> y = 0

x - 0 = 1
x = 1

4.1 - 0 + z = 2
4 - 0 + z = 2
z = 2-4
z = -2

x + y + z = 
1 + 0 - 2 = 
1 - 2 = -1