-9x2 -14x +8 = 0
ax2 bx c = 0
a = -9
b = -14
c = 8
Δ = b2-4ac
Δ = -14² - (4 * -9 * 8)
Δ = 196 - (4*-72)
Δ = 196 - (-288)
Δ = 484 Δ > 0
-9x2-14x+8=0
x = -b ∓ √Δ 2a
x' = 14 - √484 2*-9 = 14 - 22.0 -18 = -8.0 -18 = 0.444444444444
x" = 14 + √484 2*-9 = 14 + 22.0 -18 = 36.0 -18 = -2.0
x' = 36.0
x" = -162.0
S = {x ∈ R / x' = 36.0, x" = -162.0 }