Question

Matrix method solve: 4×4 order [x 4] [9 x]

Answer 1

The answer for the first one will be
${x}^{2} - 36 = 0$
That is
${x}^{2} = 36$
Which implies
$x = + or- \sqrt{36} = + or - 6$
Therefore, x = 6 or x = -6