-3x2 -17x +20 = 0
ax2 bx c = 0
a = -3
b = -17
c = 20
Δ = b2-4ac
Δ = -17² - (4 * -3 * 20)
Δ = 289 - (4*-60)
Δ = 289 - (-240)
Δ = 529 Δ > 0
-3x2-17x+20=0
x = -b ∓ √Δ 2a
x' = 17 - √529 2*-3 = 17 - 23.0 -6 = -6.0 -6 = 1.0
x" = 17 + √529 2*-3 = 17 + 23.0 -6 = 40.0 -6 = -6.66666666667
x' = 9.0
x" = -60.0
S = {x ∈ R / x' = 9.0, x" = -60.0 }