22x2 -2x -20 = 0

ax2 bx c = 0

a = 22

b = -2

c = -20

Δ = b2-4ac

Δ = -2² - (4 * 22 * -20)

Δ = 4 - (4*-440)

Δ = 4 - (-1760)

Δ = 1764      Δ > 0

22x2-2x-20=0

x = -b ∓ √Δ 2a

x' = 2 - √1764 2*22 = 2 - 42.0 44 = -40.0 44 = -0.909090909091

x" = 2 + √1764 2*22 = 2 + 42.0 44 = 44.0 44 = 1.0

x' = -440.0

x" = 484.0

S = {x ∈ R / x' = -440.0, x" = 484.0 }