-6x2 -20x -14 = 0
ax2 bx c = 0
a = -6
b = -20
c = -14
Δ = b2-4ac
Δ = -20² - (4 * -6 * -14)
Δ = 400 - (4*84)
Δ = 400 - (336)
Δ = 64 Δ > 0
-6x2-20x-14=0
x = -b ∓ √Δ 2a
x' = 20 - √64 2*-6 = 20 - 8.0 -12 = 12.0 -12 = -1.0
x" = 20 + √64 2*-6 = 20 + 8.0 -12 = 28.0 -12 = -2.33333333333
x' = -36.0
x" = -84.0
S = {x ∈ R / x' = -36.0, x" = -84.0 }