-18x2 +23x +6 = 0
ax2 bx c = 0
a = -18
b = 23
c = 6
Δ = b2-4ac
Δ = 23² - (4 * -18 * 6)
Δ = 529 - (4*-108)
Δ = 529 - (-432)
Δ = 961 Δ > 0
-18x2+23x+6=0
x = -b ∓ √Δ 2a
x' = -23 - √961 2*-18 = -23 - 31.0 -36 = -54.0 -36 = 1.5
x" = -23 + √961 2*-18 = -23 + 31.0 -36 = 8.0 -36 = -0.222222222222
x' = 486.0
x" = -72.0
S = {x ∈ R / x' = 486.0, x" = -72.0 }