Question

X elevado a dois menos seis igual a zero

Answer 1

x²-6=0
x²=0+6
x²=6
√x²=√6
x=2,44...

Answer 2

$x^2 - 6 = 0\to\\ x^2 = 6\to\\ x= \pm \sqrt{6} \\\\ S = \{ -\sqrt{6} ~;~ \sqrt{6}\}$