-1x2 +6x -5 = 0

ax2 bx c = 0

a = -1

b = 6

c = -5

Δ = b2-4ac

Δ = 6² - (4 * -1 * -5)

Δ = 36 - (4*5)

Δ = 36 - (20)

Δ = 16      Δ > 0

-x2+6x-5=0

x = -b ∓ √Δ 2a

x' = -6 - √16 2*-1 = -6 - 4.0 -2 = -10.0 -2 = 5.0

x" = -6 + √16 2*-1 = -6 + 4.0 -2 = -2.0 -2 = 1.0

x' = 5.0

x" = 1.0

S = {x ∈ R / x' = 5.0, x" = 1.0 }