-4x2 -7x -3 = 0

ax2 bx c = 0

a = -4

b = -7

c = -3

Δ = b2-4ac

Δ = -7² - (4 * -4 * -3)

Δ = 49 - (4*12)

Δ = 49 - (48)

Δ = 1      Δ > 0

-4x2-7x-3=0

x = -b ∓ √Δ 2a

x' = 7 - √1 2*-4 = 7 - 1.0 -8 = 6.0 -8 = -0.75

x" = 7 + √1 2*-4 = 7 + 1.0 -8 = 8.0 -8 = -1.0

x' = -12.0

x" = -16.0

S = {x ∈ R / x' = -12.0, x" = -16.0 }