-4x2 -x +3 = 0

ax2 bx c = 0

a = -4

b = -1

c = 3

Δ = b2-4ac

Δ = -² - (4 * -4 * 3)

Δ = 1 - (4*-12)

Δ = 1 - (-48)

Δ = 49      Δ > 0

-4x2-x+3=0

x = -b ∓ √Δ 2a

x' = 1 - √49 2*-4 = 1 - 7.0 -8 = -6.0 -8 = 0.75

x" = 1 + √49 2*-4 = 1 + 7.0 -8 = 8.0 -8 = -1.0

x' = 12.0

x" = -16.0

S = {x ∈ R / x' = 12.0, x" = -16.0 }