For what value of $x$ is $\begin{bmatrix} 4 & 2x - 1 \\ 7 & 2 \end{bmatrix}$ symmetric?

Explanation

1. 01

   A symmetric matrix equals its transpose, so $a_{12} = a_{21}$.

2. 02

   $2x - 1 = 7$ gives $x = 4$.