5x2 +16x +12 = 0
ax2 bx c = 0
a = 5
b = 16
c = 12
Δ = b2-4ac
Δ = 16² - (4 * 5 * 12)
Δ = 256 - (4*60)
Δ = 256 - (240)
Δ = 16 Δ > 0
5x2+16x+12=0
x = -b ∓ √Δ 2a
x' = -16 - √16 2*5 = -16 - 4.0 10 = -20.0 10 = -2.0
x" = -16 + √16 2*5 = -16 + 4.0 10 = -12.0 10 = -1.2
x' = -50.0
x" = -30.0
S = {x ∈ R / x' = -50.0, x" = -30.0 }