5x2 +2x -16 = 0
ax2 bx c = 0
a = 5
b = 2
c = -16
Δ = b2-4ac
Δ = 2² - (4 * 5 * -16)
Δ = 4 - (4*-80)
Δ = 4 - (-320)
Δ = 324 Δ > 0
5x2+2x-16=0
x = -b ∓ √Δ 2a
x' = -2 - √324 2*5 = -2 - 18.0 10 = -20.0 10 = -2.0
x" = -2 + √324 2*5 = -2 + 18.0 10 = 16.0 10 = 1.6
x' = -50.0
x" = 40.0
S = {x ∈ R / x' = -50.0, x" = 40.0 }