5x2 +16x -16 = 0
ax2 bx c = 0
a = 5
b = 16
c = -16
Δ = b2-4ac
Δ = 16² - (4 * 5 * -16)
Δ = 256 - (4*-80)
Δ = 256 - (-320)
Δ = 576 Δ > 0
5x2+16x-16=0
x = -b ∓ √Δ 2a
x' = -16 - √576 2*5 = -16 - 24.0 10 = -40.0 10 = -4.0
x" = -16 + √576 2*5 = -16 + 24.0 10 = 8.0 10 = 0.8
x' = -100.0
x" = 20.0
S = {x ∈ R / x' = -100.0, x" = 20.0 }