-3x2 +6x +9 = 0
ax2 bx c = 0
a = -3
b = 6
c = 9
Δ = b2-4ac
Δ = 6² - (4 * -3 * 9)
Δ = 36 - (4*-27)
Δ = 36 - (-108)
Δ = 144 Δ > 0
-3x2+6x+9=0
x = -b ∓ √Δ 2a
x' = -6 - √144 2*-3 = -6 - 12.0 -6 = -18.0 -6 = 3.0
x" = -6 + √144 2*-3 = -6 + 12.0 -6 = 6.0 -6 = -1.0
x' = 27.0
x" = -9.0
S = {x ∈ R / x' = 27.0, x" = -9.0 }