-12x2 +18x -6 = 0

ax2 bx c = 0

a = -12

b = 18

c = -6

Δ = b2-4ac

Δ = 18² - (4 * -12 * -6)

Δ = 324 - (4*72)

Δ = 324 - (288)

Δ = 36      Δ > 0

-12x2+18x-6=0

x = -b ∓ √Δ 2a

x' = -18 - √36 2*-12 = -18 - 6.0 -24 = -24.0 -24 = 1.0

x" = -18 + √36 2*-12 = -18 + 6.0 -24 = -12.0 -24 = 0.5

x' = 144.0

x" = 72.0

S = {x ∈ R / x' = 144.0, x" = 72.0 }