-3x2 +20x -12 = 0
ax2 bx c = 0
a = -3
b = 20
c = -12
Δ = b2-4ac
Δ = 20² - (4 * -3 * -12)
Δ = 400 - (4*36)
Δ = 400 - (144)
Δ = 256 Δ > 0
-3x2+20x-12=0
x = -b ∓ √Δ 2a
x' = -20 - √256 2*-3 = -20 - 16.0 -6 = -36.0 -6 = 6.0
x" = -20 + √256 2*-3 = -20 + 16.0 -6 = -4.0 -6 = 0.666666666667
x' = 54.0
x" = 6.0
S = {x ∈ R / x' = 54.0, x" = 6.0 }