-6x2 +12x +18 = 0
ax2 bx c = 0
a = -6
b = 12
c = 18
Δ = b2-4ac
Δ = 12² - (4 * -6 * 18)
Δ = 144 - (4*-108)
Δ = 144 - (-432)
Δ = 576 Δ > 0
-6x2+12x+18=0
x = -b ∓ √Δ 2a
x' = -12 - √576 2*-6 = -12 - 24.0 -12 = -36.0 -12 = 3.0
x" = -12 + √576 2*-6 = -12 + 24.0 -12 = 12.0 -12 = -1.0
x' = 108.0
x" = -36.0
S = {x ∈ R / x' = 108.0, x" = -36.0 }