Respuesta :

Step-by-step explanation:

[tex]{x}^{2} + 6x - 9 = 0[/tex]

ADDING 18 ON BOTH SIDES

[tex] { x }^{2} + 6x - 9 + 18 = 0 + 18[/tex]

[tex] {x}^{2} + 6x + 9 = 18[/tex]

[tex] {(x)}^{2} + 2(x)(3) + {(3)}^{2} = 18[/tex]

[tex] {(x + 3)}^{2} = 18[/tex]