-4x2 -13x -10 = 0
ax2 bx c = 0
a = -4
b = -13
c = -10
Δ = b2-4ac
Δ = -13² - (4 * -4 * -10)
Δ = 169 - (4*40)
Δ = 169 - (160)
Δ = 9 Δ > 0
-4x2-13x-10=0
x = -b ∓ √Δ 2a
x' = 13 - √9 2*-4 = 13 - 3.0 -8 = 10.0 -8 = -1.25
x" = 13 + √9 2*-4 = 13 + 3.0 -8 = 16.0 -8 = -2.0
x' = -20.0
x" = -32.0
S = {x ∈ R / x' = -20.0, x" = -32.0 }