-12x2 +x +11 = 0

ax2 bx c = 0

a = -12

b = 1

c = 11

Δ = b2-4ac

Δ = ² - (4 * -12 * 11)

Δ = 1 - (4*-132)

Δ = 1 - (-528)

Δ = 529      Δ > 0

-12x2+x+11=0

x = -b ∓ √Δ 2a

x' = -1 - √529 2*-12 = -1 - 23.0 -24 = -24.0 -24 = 1.0

x" = -1 + √529 2*-12 = -1 + 23.0 -24 = 22.0 -24 = -0.916666666667

x' = 144.0

x" = -132.0

S = {x ∈ R / x' = 144.0, x" = -132.0 }