-6x2 -20x -16 = 0
ax2 bx c = 0
a = -6
b = -20
c = -16
Δ = b2-4ac
Δ = -20² - (4 * -6 * -16)
Δ = 400 - (4*96)
Δ = 400 - (384)
Δ = 16 Δ > 0
-6x2-20x-16=0
x = -b ∓ √Δ 2a
x' = 20 - √16 2*-6 = 20 - 4.0 -12 = 16.0 -12 = -1.33333333333
x" = 20 + √16 2*-6 = 20 + 4.0 -12 = 24.0 -12 = -2.0
x' = -48.0
x" = -72.0
S = {x ∈ R / x' = -48.0, x" = -72.0 }