-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 = -14.0 -8 = 1.75
x" = 1 + √225 2*-4 = 1 + 15.0 -8 = 16.0 -8 = -2.0
x' = 28.0
x" = -32.0
S = {x ∈ R / x' = 28.0, x" = -32.0 }