-18x2 -16x +2 = 0
ax2 bx c = 0
a = -18
b = -16
c = 2
Δ = b2-4ac
Δ = -16² - (4 * -18 * 2)
Δ = 256 - (4*-36)
Δ = 256 - (-144)
Δ = 400 Δ > 0
-18x2-16x+2=0
x = -b ∓ √Δ 2a
x' = 16 - √400 2*-18 = 16 - 20.0 -36 = -4.0 -36 = 0.111111111111
x" = 16 + √400 2*-18 = 16 + 20.0 -36 = 36.0 -36 = -1.0
x' = 36.0
x" = -324.0
S = {x ∈ R / x' = 36.0, x" = -324.0 }