Question

If $\left[\begin{array}{cc}2x+y& 4x\\ 5x-7& 4x\end{array}\right]=\left[\begin{array}{cc}7& 7y-13\\ y& x+6\end{array}\right]$, then the value of $xandy$ is

• A. $x=3,y=1$
• B. $x=2,y=3$
• C. $x=2,y=4$
• D. $x=3,y=3$

Answer 1

Answer: (B)

$x=2,y=3$

We have, $4x=x+6\Rightarrow x=2$
And $4x=7y-13\Rightarrow 8=7y-13$
$\Rightarrow 7y=21=\Rightarrow y=3$
$\therefore x+y=2+3=5$