-3x2 -20x -17 = 0
ax2 bx c = 0
a = -3
b = -20
c = -17
Δ = b2-4ac
Δ = -20² - (4 * -3 * -17)
Δ = 400 - (4*51)
Δ = 400 - (204)
Δ = 196 Δ > 0
-3x2-20x-17=0
x = -b ∓ √Δ 2a
x' = 20 - √196 2*-3 = 20 - 14.0 -6 = 6.0 -6 = -1.0
x" = 20 + √196 2*-3 = 20 + 14.0 -6 = 34.0 -6 = -5.66666666667
x' = -9.0
x" = -51.0
S = {x ∈ R / x' = -9.0, x" = -51.0 }