If $\left|\begin{array}{cc}2 x & 5 \\ 8 & x\end{array}\right|=\left|\begin{array}{cc}6 & -2 \\ 7 & 3\end{array}\right|$ then the value of x is:

$\pm 6$

The correct answer is Option (4) → $\pm 6$

$\left|\begin{array}{cc}2 x & 5 \\ 8 & x\end{array}\right|=\left|\begin{array}{cc}6 & -2 \\ 7 & 3\end{array}\right|$

$⇒2x^2-40=18+14$

$x^2=20+9+7⇒x^2=36$

$x=\pm 6$