-12x2 -18x +12 = 0

ax2 bx c = 0

a = -12

b = -18

c = 12

Δ = b2-4ac

Δ = -18² - (4 * -12 * 12)

Δ = 324 - (4*-144)

Δ = 324 - (-576)

Δ = 900      Δ > 0

-12x2-18x+12=0

x = -b ∓ √Δ 2a

x' = 18 - √900 2*-12 = 18 - 30.0 -24 = -12.0 -24 = 0.5

x" = 18 + √900 2*-12 = 18 + 30.0 -24 = 48.0 -24 = -2.0

x' = 72.0

x" = -288.0

S = {x ∈ R / x' = 72.0, x" = -288.0 }