Question

find the value of the X from the matrix ​

Answer 1

Answer: $x=\pm\sqrt{\pm\sqrt[4]{6}+4}$

Step-by-step explanation:

By properties of determinants

$|A^4|=|A\cdot A\cdot A\cdot A|=|A|\cdot| A|\cdot| A|\cdot| A|=|A|^4$

So, since

$|A|=x\cdot x-2\cdot 2= x^2-4$

We can solve

$(x^2-4)^4=6\Longrightarrow x^2-4=\pm\sqrt[4]{6}\Longrightarrow x^2=\pm\sqrt[4]{6}+4\Longrightarrow x=\pm\sqrt{\pm\sqrt[4]{6}+4}$

(I'm guessing it was 16 instead of 6, so we can get a "better" number)