5x2 +13x -6 = 0
ax2 bx c = 0
a = 5
b = 13
c = -6
Δ = b2-4ac
Δ = 13² - (4 * 5 * -6)
Δ = 169 - (4*-30)
Δ = 169 - (-120)
Δ = 289 Δ > 0
5x2+13x-6=0
x = -b ∓ √Δ 2a
x' = -13 - √289 2*5 = -13 - 17.0 10 = -30.0 10 = -3.0
x" = -13 + √289 2*5 = -13 + 17.0 10 = 4.0 10 = 0.4
x' = -75.0
x" = 10.0
S = {x ∈ R / x' = -75.0, x" = 10.0 }