-12x2 -19x -5 = 0
ax2 bx c = 0
a = -12
b = -19
c = -5
Δ = b2-4ac
Δ = -19² - (4 * -12 * -5)
Δ = 361 - (4*60)
Δ = 361 - (240)
Δ = 121 Δ > 0
-12x2-19x-5=0
x = -b ∓ √Δ 2a
x' = 19 - √121 2*-12 = 19 - 11.0 -24 = 8.0 -24 = -0.333333333333
x" = 19 + √121 2*-12 = 19 + 11.0 -24 = 30.0 -24 = -1.25
x' = -48.0
x" = -180.0
S = {x ∈ R / x' = -48.0, x" = -180.0 }