5x2 -16x +11 = 0
ax2 bx c = 0
a = 5
b = -16
c = 11
Δ = b2-4ac
Δ = -16² - (4 * 5 * 11)
Δ = 256 - (4*55)
Δ = 256 - (220)
Δ = 36 Δ > 0
5x2-16x+11=0
x = -b ∓ √Δ 2a
x' = 16 - √36 2*5 = 16 - 6.0 10 = 10.0 10 = 1.0
x" = 16 + √36 2*5 = 16 + 6.0 10 = 22.0 10 = 2.2
x' = 25.0
x" = 55.0
S = {x ∈ R / x' = 25.0, x" = 55.0 }