-12x2 -14x +20 = 0

ax2 bx c = 0

a = -12

b = -14

c = 20

Δ = b2-4ac

Δ = -14² - (4 * -12 * 20)

Δ = 196 - (4*-240)

Δ = 196 - (-960)

Δ = 1156      Δ > 0

-12x2-14x+20=0

x = -b ∓ √Δ 2a

x' = 14 - √1156 2*-12 = 14 - 34.0 -24 = -20.0 -24 = 0.833333333333

x" = 14 + √1156 2*-12 = 14 + 34.0 -24 = 48.0 -24 = -2.0

x' = 120.0

x" = -288.0

S = {x ∈ R / x' = 120.0, x" = -288.0 }