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 = -30.0 10 = -3.0

x" = -14 + √256 2*5 = -14 + 16.0 10 = 2.0 10 = 0.2

x' = -75.0

x" = 5.0

S = {x ∈ R / x' = -75.0, x" = 5.0 }