-6x2 -19x -10 = 0

ax2 bx c = 0

a = -6

b = -19

c = -10

Δ = b2-4ac

Δ = -19² - (4 * -6 * -10)

Δ = 361 - (4*60)

Δ = 361 - (240)

Δ = 121      Δ > 0

-6x2-19x-10=0

x = -b ∓ √Δ 2a

x' = 19 - √121 2*-6 = 19 - 11.0 -12 = 8.0 -12 = -0.666666666667

x" = 19 + √121 2*-6 = 19 + 11.0 -12 = 30.0 -12 = -2.5

x' = -24.0

x" = -90.0

S = {x ∈ R / x' = -24.0, x" = -90.0 }