-4x2 -12x -8 = 0
ax2 bx c = 0
a = -4
b = -12
c = -8
Δ = b2-4ac
Δ = -12² - (4 * -4 * -8)
Δ = 144 - (4*32)
Δ = 144 - (128)
Δ = 16 Δ > 0
-4x2-12x-8=0
x = -b ∓ √Δ 2a
x' = 12 - √16 2*-4 = 12 - 4.0 -8 = 8.0 -8 = -1.0
x" = 12 + √16 2*-4 = 12 + 4.0 -8 = 16.0 -8 = -2.0
x' = -16.0
x" = -32.0
S = {x ∈ R / x' = -16.0, x" = -32.0 }