-4x2 -18x -8 = 0
ax2 bx c = 0
a = -4
b = -18
c = -8
Δ = b2-4ac
Δ = -18² - (4 * -4 * -8)
Δ = 324 - (4*32)
Δ = 324 - (128)
Δ = 196 Δ > 0
-4x2-18x-8=0
x = -b ∓ √Δ 2a
x' = 18 - √196 2*-4 = 18 - 14.0 -8 = 4.0 -8 = -0.5
x" = 18 + √196 2*-4 = 18 + 14.0 -8 = 32.0 -8 = -4.0
x' = -8.0
x" = -64.0
S = {x ∈ R / x' = -8.0, x" = -64.0 }