-12x2 +20x -3 = 0

ax2 bx c = 0

a = -12

b = 20

c = -3

Δ = b2-4ac

Δ = 20² - (4 * -12 * -3)

Δ = 400 - (4*36)

Δ = 400 - (144)

Δ = 256      Δ > 0

-12x2+20x-3=0

x = -b ∓ √Δ 2a

x' = -20 - √256 2*-12 = -20 - 16.0 -24 = -36.0 -24 = 1.5

x" = -20 + √256 2*-12 = -20 + 16.0 -24 = -4.0 -24 = 0.166666666667

x' = 216.0

x" = 24.0

S = {x ∈ R / x' = 216.0, x" = 24.0 }