-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 = -48.0 -24 = 2.0

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

x' = 288.0

x" = -72.0

S = {x ∈ R / x' = 288.0, x" = -72.0 }