22x2 +21x +5 = 0

ax2 bx c = 0

a = 22

b = 21

c = 5

Δ = b2-4ac

Δ = 21² - (4 * 22 * 5)

Δ = 441 - (4*110)

Δ = 441 - (440)

Δ = 1      Δ > 0

22x2+21x+5=0

x = -b ∓ √Δ 2a

x' = -21 - √1 2*22 = -21 - 1.0 44 = -22.0 44 = -0.5

x" = -21 + √1 2*22 = -21 + 1.0 44 = -20.0 44 = -0.454545454545

x' = -242.0

x" = -220.0

S = {x ∈ R / x' = -242.0, x" = -220.0 }