Question

Determine as soluções das equações a seguir:
2x ao quadrado-18=0

Answer 1

2ײ-18=0
2ײ=18
ײ=18\2
ײ=9
×=3

Answer 2

$2x^2-18=0\to\\ \\ 2x^2=18\to \\\\x^2= \frac{18}{2} \to \\\\x^2=9\to\\\\ x=\pm \sqrt{9} \to \\\\ x=\pm 3\\\\\\ S\{-3;3\}$