-4x2 -13x -3 = 0
ax2 bx c = 0
a = -4
b = -13
c = -3
Δ = b2-4ac
Δ = -13² - (4 * -4 * -3)
Δ = 169 - (4*12)
Δ = 169 - (48)
Δ = 121 Δ > 0
-4x2-13x-3=0
x = -b ∓ √Δ 2a
x' = 13 - √121 2*-4 = 13 - 11.0 -8 = 2.0 -8 = -0.25
x" = 13 + √121 2*-4 = 13 + 11.0 -8 = 24.0 -8 = -3.0
x' = -4.0
x" = -48.0
S = {x ∈ R / x' = -4.0, x" = -48.0 }