-4x2 +6x +10 = 0

ax2 bx c = 0

a = -4

b = 6

c = 10

Δ = b2-4ac

Δ = 6² - (4 * -4 * 10)

Δ = 36 - (4*-40)

Δ = 36 - (-160)

Δ = 196      Δ > 0

-4x2+6x+10=0

x = -b ∓ √Δ 2a

x' = -6 - √196 2*-4 = -6 - 14.0 -8 = -20.0 -8 = 2.5

x" = -6 + √196 2*-4 = -6 + 14.0 -8 = 8.0 -8 = -1.0

x' = 40.0

x" = -16.0

S = {x ∈ R / x' = 40.0, x" = -16.0 }