If the matrix $\begin{bmatrix}-3 & x-y & 5\\1& 0 & z\\x+y & 4 & 7\end{bmatrix}$ is symmetric, then the correct option of the following, is : |
$x=3, y=-1, z=1 $ $x=1, y=-1, z=4 $ $x=3, y=2, z=4 $ $x=1, y=2, z=4 $ |
$x=3, y=2, z=4 $ |
Given matrix: $\begin{pmatrix} -3 & x-y & 5 \\ 1 & 0 & z \\ x+y & 4 & 7 \end{pmatrix}$ For a symmetric matrix, $a_{ij}=a_{ji}$. So: $x-y=1$ …(1) $5=x+y$ …(2) $z=4$ …(3) Add (1) and (2): $2x=6 \Rightarrow x=3$ Substitute in (2): $3+y=5 \Rightarrow y=2$ From (3): $z=4$ final answer: $x=3,\;y=2,\;z=4$ |