If $X+Y=\begin{bmatrix}7 & 0\\2 & 5\end{bmatrix}$ and $X-Y=\begin{bmatrix}3 & 0 \\0 & 3\end{bmatrix}$. Then X and Y are :
Answer & explanation
Correct answer: option 1
The correct answer is Option (1) → $X=\begin{bmatrix}5 & 0\\1 & 4\end{bmatrix}$ and $Y=\begin{bmatrix}2 & 0\\1 & 1\end{bmatrix}$
$X+Y=\begin{bmatrix}7 & 0\\2 & 5\end{bmatrix}$ ....(1)
$X-Y=\begin{bmatrix}3 & 0 \\0 & 3\end{bmatrix}$ ....(2)
$X+Y+X-Y=\begin{bmatrix}10 & 0\\2 & 8\end{bmatrix}$
$2X=\begin{bmatrix}10 & 0\\2 & 8\end{bmatrix}⇒X=\begin{bmatrix}5& 0\\1 & 4\end{bmatrix}$
so from (1)
$Y=\begin{bmatrix}7& 0\\2 & 5\end{bmatrix}-\begin{bmatrix}5& 0\\1 & 4\end{bmatrix}$
$Y=\begin{bmatrix}2 & 0\\1 & 1\end{bmatrix}$