-12x2 -11x +23 = 0

ax2 bx c = 0

a = -12

b = -11

c = 23

Δ = b2-4ac

Δ = -11² - (4 * -12 * 23)

Δ = 121 - (4*-276)

Δ = 121 - (-1104)

Δ = 1225      Δ > 0

-12x2-11x+23=0

x = -b ∓ √Δ 2a

x' = 11 - √1225 2*-12 = 11 - 35.0 -24 = -24.0 -24 = 1.0

x" = 11 + √1225 2*-12 = 11 + 35.0 -24 = 46.0 -24 = -1.91666666667

x' = 144.0

x" = -276.0

S = {x ∈ R / x' = 144.0, x" = -276.0 }