-4x2 +17x -4 = 0

ax2 bx c = 0

a = -4

b = 17

c = -4

Δ = b2-4ac

Δ = 17² - (4 * -4 * -4)

Δ = 289 - (4*16)

Δ = 289 - (64)

Δ = 225      Δ > 0

-4x2+17x-4=0

x = -b ∓ √Δ 2a

x' = -17 - √225 2*-4 = -17 - 15.0 -8 = -32.0 -8 = 4.0

x" = -17 + √225 2*-4 = -17 + 15.0 -8 = -2.0 -8 = 0.25

x' = 64.0

x" = 4.0

S = {x ∈ R / x' = 64.0, x" = 4.0 }