-6x2 -3x +18 = 0
ax2 bx c = 0
a = -6
b = -3
c = 18
Δ = b2-4ac
Δ = -3² - (4 * -6 * 18)
Δ = 9 - (4*-108)
Δ = 9 - (-432)
Δ = 441 Δ > 0
-6x2-3x+18=0
x = -b ∓ √Δ 2a
x' = 3 - √441 2*-6 = 3 - 21.0 -12 = -18.0 -12 = 1.5
x" = 3 + √441 2*-6 = 3 + 21.0 -12 = 24.0 -12 = -2.0
x' = 54.0
x" = -72.0
S = {x ∈ R / x' = 54.0, x" = -72.0 }