-6x2 -19x -14 = 0

ax2 bx c = 0

a = -6

b = -19

c = -14

Δ = b2-4ac

Δ = -19² - (4 * -6 * -14)

Δ = 361 - (4*84)

Δ = 361 - (336)

Δ = 25      Δ > 0

-6x2-19x-14=0

x = -b ∓ √Δ 2a

x' = 19 - √25 2*-6 = 19 - 5.0 -12 = 14.0 -12 = -1.16666666667

x" = 19 + √25 2*-6 = 19 + 5.0 -12 = 24.0 -12 = -2.0

x' = -42.0

x" = -72.0

S = {x ∈ R / x' = -42.0, x" = -72.0 }