-12x2 -11x +1 = 0

ax2 bx c = 0

a = -12

b = -11

c = 1

Δ = b2-4ac

Δ = -11² - (4 * -12 * 1)

Δ = 121 - (4*-12)

Δ = 121 - (-48)

Δ = 169      Δ > 0

-12x2-11x+1=0

x = -b ∓ √Δ 2a

x' = 11 - √169 2*-12 = 11 - 13.0 -24 = -2.0 -24 = 0.0833333333333

x" = 11 + √169 2*-12 = 11 + 13.0 -24 = 24.0 -24 = -1.0

x' = 12.0

x" = -144.0

S = {x ∈ R / x' = 12.0, x" = -144.0 }