-6x2 -20x -6 = 0
ax2 bx c = 0
a = -6
b = -20
c = -6
Δ = b2-4ac
Δ = -20² - (4 * -6 * -6)
Δ = 400 - (4*36)
Δ = 400 - (144)
Δ = 256 Δ > 0
-6x2-20x-6=0
x = -b ∓ √Δ 2a
x' = 20 - √256 2*-6 = 20 - 16.0 -12 = 4.0 -12 = -0.333333333333
x" = 20 + √256 2*-6 = 20 + 16.0 -12 = 36.0 -12 = -3.0
x' = -12.0
x" = -108.0
S = {x ∈ R / x' = -12.0, x" = -108.0 }