Question

If $A=\left[\begin{array}{cc}4& x+2\\ 2x-3& x+1\end{array}\right]$ is symmetric, then x=

• A. 3
• B. 5
• C. 2
• D. 4

Answer 1

The correct option is B 5

Given $A=\left[\begin{array}{cc}4& x+2\\ 2x-3& x+1\end{array}\right]$ is symmteric.
$A^T=A$
$\Rightarrow \left[\begin{array}{cc}4& 2x-3\\ x+2& x+1\end{array}\right]=\left[\begin{array}{cc}4& x+2\\ 2x-3& x+1\end{array}\right]$
$\Rightarrow x+2=2x-3$
$\Rightarrow x=5$