5x2 +5x -10 = 0

ax2 bx c = 0

a = 5

b = 5

c = -10

Δ = b2-4ac

Δ = 5² - (4 * 5 * -10)

Δ = 25 - (4*-50)

Δ = 25 - (-200)

Δ = 225      Δ > 0

5x2+5x-10=0

x = -b ∓ √Δ 2a

x' = -5 - √225 2*5 = -5 - 15.0 10 = -20.0 10 = -2.0

x" = -5 + √225 2*5 = -5 + 15.0 10 = 10.0 10 = 1.0

x' = -50.0

x" = 25.0

S = {x ∈ R / x' = -50.0, x" = 25.0 }