Question

preciso urgente
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Answer 1

Explicação passo a passo:

$3\cdot\left[\begin{array}{cc}x&2\\-z&1\end{array}\right]-\left[\begin{array}{cc}y&6\\5&y\end{array}\right]=\left[\begin{array}{cc}7&0\\10&4\end{array}\right]$

Logo:

$\left[\begin{array}{cc}3x&6\\-3z&3\end{array}\right]-\left[\begin{array}{cc}y&6\\5&y\end{array}\right]=\left[\begin{array}{cc}7&0\\10&4\end{array}\right]\\\left[\begin{array}{cc}3x-y&6-6\\-3z-5&3-y\end{array}\right]=\left[\begin{array}{cc}7&0\\10&4\end{array}\right]$

Transformando em um sistema de equações:

$\begin{cases} 3x-y=7\quad\quad(I)\\-3z-5=10\quad\quad (II)\\3-y=4 \quad\quad(III) \end{cases}$

Resolvendo a equação $(II)$:

$-3z-5=10\\-3z=15\\z=-5$

Resolvendo a equação $(III)$:

$3-y=4\\-y=1\\y=-1$

Substituindo o valor de $y$ em $(I)$:

$3x-y=7\\3x-(-1)=7\\3x+1=7\\3x=6\\x=2$

Portanto: $x=2,y=-1,z=-5$