1x2 +x -6 = 0
ax2 bx c = 0
a = 1
b = 1
c = -6
Δ = b2-4ac
Δ = ² - (4 * 1 * -6)
Δ = 1 - (4*-6)
Δ = 1 - (-24)
Δ = 25 Δ > 0
x2+x-6=0
x = -b ∓ √Δ 2a
x' = -1 - √25 2*1 = -1 - 5.0 2 = -6.0 2 = -3.0
x" = -1 + √25 2*1 = -1 + 5.0 2 = 4.0 2 = 2.0
x' = -3.0
x" = 2.0
S = {x ∈ R / x' = -3.0, x" = 2.0 }