Question

$2x^{2} -12x+18=0$

Answer 1

2x² - 12x + 18 = 0 (:2)
x² - 6x + 9 = 0
x² - 3x - 3x + 9 = 0
x.(x - 3) - 3.(x - 3) = 0
(x - 3).(x - 3) = 0

x - 3 = 0
x = 3

R.: x = 3
***************************************
Ou por Báscara:


x² - 6x + 9 = 0
a = 1; b = - 6; c = 9
Δ = b² - 4ac
Δ = (-6)² - 4.1.9
Δ = 36 - 36
Δ = 0

x = - b +/- √Δ
      --------------
            2a

x = - (-6) +/- 0
      ----------------  = 6/2 = 3
               2.1

R.: x = 3