-18x2 +x +17 = 0
ax2 bx c = 0
a = -18
b = 1
c = 17
Δ = b2-4ac
Δ = ² - (4 * -18 * 17)
Δ = 1 - (4*-306)
Δ = 1 - (-1224)
Δ = 1225 Δ > 0
-18x2+x+17=0
x = -b ∓ √Δ 2a
x' = -1 - √1225 2*-18 = -1 - 35.0 -36 = -36.0 -36 = 1.0
x" = -1 + √1225 2*-18 = -1 + 35.0 -36 = 34.0 -36 = -0.944444444444
x' = 324.0
x" = -306.0
S = {x ∈ R / x' = 324.0, x" = -306.0 }