Question

If $\left[\begin{array}{cc}x-y& z\\ 2x-y& w\end{array}\right]=\left[\begin{array}{cc}-1& 4\\ 0& 5\end{array}\right]$, then find the value of $x+y$.

Answer 1

On comparing the corresponding elements, we get,

$x-y=-1$ and $2x-y=0$

On solving the above equations, we get,

$x=1$ and $y=2$

Now, $x+y=1+2=3$