Question

raiz de (x+8)(x+3)=6

Answer 1

(x + 8)(x + 3) = 6
x² + 3x + 8x + 24 = 6
x² + 11x + 24 - 6 = 0
x² + 11x + 18 = 0 <<<<<<<<<<
Delta = b² - 4ac
Delta = 121 - 4(1)(18)
Delta = 121 - 72
Delta = 49
X = (-b +- raiz delta) / 2a
X = (-11 +- 7) / 2
x' = (-11 + 7) / 2 = -4/2 = -2
x" = (-11 - 7) / 2 = -18/2 = -9

Answer 2

(x + 8).(x + 3) = 6
x² + 3x + 8x + 24 = 6
x² + 11x + 24 - 6 = 0
x² + 11x + 18 = 0
a = 1; b= 11; c = 18

Δ = b² - 4ac
Δ = 11² - 4.1.18
Δ = 121 - 72
Δ = 49

x = - b +/- √Δ = - 11 +/- √49      
          2a               2.1

x = - 11 + 7 = - 4/2 = - 2
         2
x = - 11 - 7 = - 18/2 = - 9
          2