18x2 -20x +2 = 0
ax2 bx c = 0
a = 18
b = -20
c = 2
Δ = b2-4ac
Δ = -20² - (4 * 18 * 2)
Δ = 400 - (4*36)
Δ = 400 - (144)
Δ = 256 Δ > 0
18x2-20x+2=0
x = -b ∓ √Δ 2a
x' = 20 - √256 2*18 = 20 - 16.0 36 = 4.0 36 = 0.111111111111
x" = 20 + √256 2*18 = 20 + 16.0 36 = 36.0 36 = 1.0
x' = 36.0
x" = 324.0
S = {x ∈ R / x' = 36.0, x" = 324.0 }