-1x2 -12x -11 = 0
ax2 bx c = 0
a = -1
b = -12
c = -11
Δ = b2-4ac
Δ = -12² - (4 * -1 * -11)
Δ = 144 - (4*11)
Δ = 144 - (44)
Δ = 100 Δ > 0
-x2-12x-11=0
x = -b ∓ √Δ 2a
x' = 12 - √100 2*-1 = 12 - 10.0 -2 = 2.0 -2 = -1.0
x" = 12 + √100 2*-1 = 12 + 10.0 -2 = 22.0 -2 = -11.0
x' = -1.0
x" = -11.0
S = {x ∈ R / x' = -1.0, x" = -11.0 }