-4x2 +x +14 = 0

ax2 bx c = 0

a = -4

b = 1

c = 14

Δ = b2-4ac

Δ = ² - (4 * -4 * 14)

Δ = 1 - (4*-56)

Δ = 1 - (-224)

Δ = 225      Δ > 0

-4x2+x+14=0

x = -b ∓ √Δ 2a

x' = -1 - √225 2*-4 = -1 - 15.0 -8 = -16.0 -8 = 2.0

x" = -1 + √225 2*-4 = -1 + 15.0 -8 = 14.0 -8 = -1.75

x' = 32.0

x" = -28.0

S = {x ∈ R / x' = 32.0, x" = -28.0 }