Question

If $3\left[\begin{array}{cc}4& 2\\ 1& 3\end{array}\right]-2\left[\begin{array}{cc}-2& 1\\ 3& 2\end{array}\right]+\left[\begin{array}{cc}x& -4\\ 3& y\end{array}\right]=0,$ then $(x,y)=$

• A. $\left(165\right)$
• B. $\left(516\right)$
• C. $(-16-5)$
• D. $(-5-16)$

Answer 1

The correct option is C $(-16-5)$

$3\left[\begin{array}{cc}4& 2\\ 1& 3\end{array}\right]-2\left[\begin{array}{cc}-2& 1\\ 3& 2\end{array}\right]+\left[\begin{array}{cc}x& -4\\ 3& y\end{array}\right]=0$

$\Rightarrow \left[\begin{array}{cc}12+4+x& 6-2-4\\ 3-6+3& 9-4+y\end{array}\right]=\left[\begin{array}{cc}0& 0\\ 0& 0\end{array}\right]$

$\Rightarrow x=-16,y=-5$