-12x2 -19x -7 = 0
ax2 bx c = 0
a = -12
b = -19
c = -7
Δ = b2-4ac
Δ = -19² - (4 * -12 * -7)
Δ = 361 - (4*84)
Δ = 361 - (336)
Δ = 25 Δ > 0
-12x2-19x-7=0
x = -b ∓ √Δ 2a
x' = 19 - √25 2*-12 = 19 - 5.0 -24 = 14.0 -24 = -0.583333333333
x" = 19 + √25 2*-12 = 19 + 5.0 -24 = 24.0 -24 = -1.0
x' = -84.0
x" = -144.0
S = {x ∈ R / x' = -84.0, x" = -144.0 }