Question

1) 2x² - 18 = 0

2) 6x² + 12x= 0

3) x² + 2x + 1= 0

Answer 1

hola Loquita2017,

1)
2x² - 18 = 0
2x² = 18
$x^{2} = \frac{18}{2}$
$x = \sqrt{9}$
x=3

2)
6x² +12x = 0
x² + 2x = 0         [se simplifico, dividiendo en 6]
x(x+2)=0

$x_{1} = 0$                       $x_{2} = -2$

3)
x² + 2x + 1 = 0
(x+1)²= 0
x= -1