5x2 +15x +10 = 0
ax2 bx c = 0
a = 5
b = 15
c = 10
Δ = b2-4ac
Δ = 15² - (4 * 5 * 10)
Δ = 225 - (4*50)
Δ = 225 - (200)
Δ = 25 Δ > 0
5x2+15x+10=0
x = -b ∓ √Δ 2a
x' = -15 - √25 2*5 = -15 - 5.0 10 = -20.0 10 = -2.0
x" = -15 + √25 2*5 = -15 + 5.0 10 = -10.0 10 = -1.0
x' = -50.0
x" = -25.0
S = {x ∈ R / x' = -50.0, x" = -25.0 }