-3x2 +20x -17 = 0

ax2 bx c = 0

a = -3

b = 20

c = -17

Δ = b2-4ac

Δ = 20² - (4 * -3 * -17)

Δ = 400 - (4*51)

Δ = 400 - (204)

Δ = 196      Δ > 0

-3x2+20x-17=0

x = -b ∓ √Δ 2a

x' = -20 - √196 2*-3 = -20 - 14.0 -6 = -34.0 -6 = 5.66666666667

x" = -20 + √196 2*-3 = -20 + 14.0 -6 = -6.0 -6 = 1.0

x' = 51.0

x" = 9.0

S = {x ∈ R / x' = 51.0, x" = 9.0 }