-4x2 -12x +16 = 0

ax2 bx c = 0

a = -4

b = -12

c = 16

Δ = b2-4ac

Δ = -12² - (4 * -4 * 16)

Δ = 144 - (4*-64)

Δ = 144 - (-256)

Δ = 400      Δ > 0

-4x2-12x+16=0

x = -b ∓ √Δ 2a

x' = 12 - √400 2*-4 = 12 - 20.0 -8 = -8.0 -8 = 1.0

x" = 12 + √400 2*-4 = 12 + 20.0 -8 = 32.0 -8 = -4.0

x' = 16.0

x" = -64.0

S = {x ∈ R / x' = 16.0, x" = -64.0 }