5x2 +22x +8 = 0
ax2 bx c = 0
a = 5
b = 22
c = 8
Δ = b2-4ac
Δ = 22² - (4 * 5 * 8)
Δ = 484 - (4*40)
Δ = 484 - (160)
Δ = 324 Δ > 0
5x2+22x+8=0
x = -b ∓ √Δ 2a
x' = -22 - √324 2*5 = -22 - 18.0 10 = -40.0 10 = -4.0
x" = -22 + √324 2*5 = -22 + 18.0 10 = -4.0 10 = -0.4
x' = -100.0
x" = -10.0
S = {x ∈ R / x' = -100.0, x" = -10.0 }