-4x2 -6x +18 = 0
ax2 bx c = 0
a = -4
b = -6
c = 18
Δ = b2-4ac
Δ = -6² - (4 * -4 * 18)
Δ = 36 - (4*-72)
Δ = 36 - (-288)
Δ = 324 Δ > 0
-4x2-6x+18=0
x = -b ∓ √Δ 2a
x' = 6 - √324 2*-4 = 6 - 18.0 -8 = -12.0 -8 = 1.5
x" = 6 + √324 2*-4 = 6 + 18.0 -8 = 24.0 -8 = -3.0
x' = 24.0
x" = -48.0
S = {x ∈ R / x' = 24.0, x" = -48.0 }