-12x2 -20x -8 = 0
ax2 bx c = 0
a = -12
b = -20
c = -8
Δ = b2-4ac
Δ = -20² - (4 * -12 * -8)
Δ = 400 - (4*96)
Δ = 400 - (384)
Δ = 16 Δ > 0
-12x2-20x-8=0
x = -b ∓ √Δ 2a
x' = 20 - √16 2*-12 = 20 - 4.0 -24 = 16.0 -24 = -0.666666666667
x" = 20 + √16 2*-12 = 20 + 4.0 -24 = 24.0 -24 = -1.0
x' = -96.0
x" = -144.0
S = {x ∈ R / x' = -96.0, x" = -144.0 }