Question

Please help (Math)......

Answer 1

$|x|^2 -2|x|-3=0\\\\\implies |x|^2 - 3|x| + |x| - 3 =0\\\\\implies |x|(|x| -3) + (|x| -3) = 0\\\\\implies (|x| - 3)(|x| +1) =0\\\\\implies |x| -3 = 0~~ \text{Or} ~~ |x| +1 =0\\\\\implies |x| = 3 ~~ \text{Or}~~ |x| = -1;\\\\\text{For}~ |x|= -1 ,~\text{ there are no solution for } x \in \mathbb{R}\\\\\text{So,}\\\\|x| = 3 \implies x = \pm 3$