Question

If $\left[\begin{array}{cc}x& 0\\ 1& y\end{array}\right]+\left[\begin{array}{cc}-2& 1\\ 3& 4\end{array}\right]=\left[\begin{array}{cc}3& 5\\ 6& 3\end{array}\right]-\left[\begin{array}{cc}2& 4\\ 2& 1\end{array}\right]$, then

• A. $x=-3,y=-2$
• B. $x=3,y=-2$
• C. $x=3,y=2$
• D. $x=-3,y=2$

Answer 1

The correct option is B $x=3,y=-2$

Since, $\left[\begin{array}{cc}x& 0\\ 1& y\end{array}\right]+\left[\begin{array}{cc}-2& 1\\ 3& 4\end{array}\right]=\left[\begin{array}{cc}3& 5\\ 6& 3\end{array}\right]-\left[\begin{array}{cc}2& 4\\ 2& 1\end{array}\right]$
$\Rightarrow \left[\begin{array}{cc}x-2& 1\\ 4& y+4\end{array}\right]=\left[\begin{array}{cc}1& 1\\ 4& 2\end{array}\right]$
$\Rightarrow x-2=1$ and $y+4=2$
$\Rightarrow x=3,y=-2$