-4x2 +22x -10 = 0

ax2 bx c = 0

a = -4

b = 22

c = -10

Δ = b2-4ac

Δ = 22² - (4 * -4 * -10)

Δ = 484 - (4*40)

Δ = 484 - (160)

Δ = 324      Δ > 0

-4x2+22x-10=0

x = -b ∓ √Δ 2a

x' = -22 - √324 2*-4 = -22 - 18.0 -8 = -40.0 -8 = 5.0

x" = -22 + √324 2*-4 = -22 + 18.0 -8 = -4.0 -8 = 0.5

x' = 80.0

x" = 8.0

S = {x ∈ R / x' = 80.0, x" = 8.0 }