-12x2 -18x -6 = 0
ax2 bx c = 0
a = -12
b = -18
c = -6
Δ = b2-4ac
Δ = -18² - (4 * -12 * -6)
Δ = 324 - (4*72)
Δ = 324 - (288)
Δ = 36 Δ > 0
-12x2-18x-6=0
x = -b ∓ √Δ 2a
x' = 18 - √36 2*-12 = 18 - 6.0 -24 = 12.0 -24 = -0.5
x" = 18 + √36 2*-12 = 18 + 6.0 -24 = 24.0 -24 = -1.0
x' = -72.0
x" = -144.0
S = {x ∈ R / x' = -72.0, x" = -144.0 }