5x2 +7x -6 = 0
ax2 bx c = 0
a = 5
b = 7
c = -6
Δ = b2-4ac
Δ = 7² - (4 * 5 * -6)
Δ = 49 - (4*-30)
Δ = 49 - (-120)
Δ = 169 Δ > 0
5x2+7x-6=0
x = -b ∓ √Δ 2a
x' = -7 - √169 2*5 = -7 - 13.0 10 = -20.0 10 = -2.0
x" = -7 + √169 2*5 = -7 + 13.0 10 = 6.0 10 = 0.6
x' = -50.0
x" = 15.0
S = {x ∈ R / x' = -50.0, x" = 15.0 }