-18x2 -17x +1 = 0
ax2 bx c = 0
a = -18
b = -17
c = 1
Δ = b2-4ac
Δ = -17² - (4 * -18 * 1)
Δ = 289 - (4*-18)
Δ = 289 - (-72)
Δ = 361 Δ > 0
-18x2-17x+1=0
x = -b ∓ √Δ 2a
x' = 17 - √361 2*-18 = 17 - 19.0 -36 = -2.0 -36 = 0.0555555555556
x" = 17 + √361 2*-18 = 17 + 19.0 -36 = 36.0 -36 = -1.0
x' = 18.0
x" = -324.0
S = {x ∈ R / x' = 18.0, x" = -324.0 }