-9x2 +23x -14 = 0
ax2 bx c = 0
a = -9
b = 23
c = -14
Δ = b2-4ac
Δ = 23² - (4 * -9 * -14)
Δ = 529 - (4*126)
Δ = 529 - (504)
Δ = 25 Δ > 0
-9x2+23x-14=0
x = -b ∓ √Δ 2a
x' = -23 - √25 2*-9 = -23 - 5.0 -18 = -28.0 -18 = 1.55555555556
x" = -23 + √25 2*-9 = -23 + 5.0 -18 = -18.0 -18 = 1.0
x' = 126.0
x" = 81.0
S = {x ∈ R / x' = 126.0, x" = 81.0 }