5x2 +12x -17 = 0
ax2 bx c = 0
a = 5
b = 12
c = -17
Δ = b2-4ac
Δ = 12² - (4 * 5 * -17)
Δ = 144 - (4*-85)
Δ = 144 - (-340)
Δ = 484 Δ > 0
5x2+12x-17=0
x = -b ∓ √Δ 2a
x' = -12 - √484 2*5 = -12 - 22.0 10 = -34.0 10 = -3.4
x" = -12 + √484 2*5 = -12 + 22.0 10 = 10.0 10 = 1.0
x' = -85.0
x" = 25.0
S = {x ∈ R / x' = -85.0, x" = 25.0 }