-4x2 -4x +8 = 0

ax2 bx c = 0

a = -4

b = -4

c = 8

Δ = b2-4ac

Δ = -4² - (4 * -4 * 8)

Δ = 16 - (4*-32)

Δ = 16 - (-128)

Δ = 144      Δ > 0

-4x2-4x+8=0

x = -b ∓ √Δ 2a

x' = 4 - √144 2*-4 = 4 - 12.0 -8 = -8.0 -8 = 1.0

x" = 4 + √144 2*-4 = 4 + 12.0 -8 = 16.0 -8 = -2.0

x' = 16.0

x" = -32.0

S = {x ∈ R / x' = 16.0, x" = -32.0 }