-4x2 +23x +6 = 0

ax2 bx c = 0

a = -4

b = 23

c = 6

Δ = b2-4ac

Δ = 23² - (4 * -4 * 6)

Δ = 529 - (4*-24)

Δ = 529 - (-96)

Δ = 625      Δ > 0

-4x2+23x+6=0

x = -b ∓ √Δ 2a

x' = -23 - √625 2*-4 = -23 - 25.0 -8 = -48.0 -8 = 6.0

x" = -23 + √625 2*-4 = -23 + 25.0 -8 = 2.0 -8 = -0.25

x' = 96.0

x" = -4.0

S = {x ∈ R / x' = 96.0, x" = -4.0 }