5x2 -14x -3 = 0
ax2 bx c = 0
a = 5
b = -14
c = -3
Δ = b2-4ac
Δ = -14² - (4 * 5 * -3)
Δ = 196 - (4*-15)
Δ = 196 - (-60)
Δ = 256 Δ > 0
5x2-14x-3=0
x = -b ∓ √Δ 2a
x' = 14 - √256 2*5 = 14 - 16.0 10 = -2.0 10 = -0.2
x" = 14 + √256 2*5 = 14 + 16.0 10 = 30.0 10 = 3.0
x' = -5.0
x" = 75.0
S = {x ∈ R / x' = -5.0, x" = 75.0 }