If $A=\begin{bmatrix}2+x & y\\1 & 5\end{bmatrix}$ and $B=\begin{bmatrix}3+y & x-1\\2 & 10 \end{bmatrix}$ such that B=2A, then value of x and y are respectively :
Answer & explanation
Correct answer: option 3
The correct answer is option (3) → -1, -1
$B=2A⇒\begin{bmatrix}3+y & x-1\\2 & 10 \end{bmatrix}=\begin{bmatrix}4+2x & 2y\\2 & 10\end{bmatrix}$
on comparison
$x-1=2y$
$⇒x=1+2y$
$3+y=4+2x$
$3+y=4+2+4y$
$-3=3y⇒y=-1$
$⇒x=-1$
$x=-1,y=-1$