-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 = -24.0 -24 = 1.0

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

x' = 144.0

x" = -12.0

S = {x ∈ R / x' = 144.0, x" = -12.0 }