-9x2 -11x +14 = 0
ax2 bx c = 0
a = -9
b = -11
c = 14
Δ = b2-4ac
Δ = -11² - (4 * -9 * 14)
Δ = 121 - (4*-126)
Δ = 121 - (-504)
Δ = 625 Δ > 0
-9x2-11x+14=0
x = -b ∓ √Δ 2a
x' = 11 - √625 2*-9 = 11 - 25.0 -18 = -14.0 -18 = 0.777777777778
x" = 11 + √625 2*-9 = 11 + 25.0 -18 = 36.0 -18 = -2.0
x' = 63.0
x" = -162.0
S = {x ∈ R / x' = 63.0, x" = -162.0 }