-4x2 -18x +10 = 0
ax2 bx c = 0
a = -4
b = -18
c = 10
Δ = b2-4ac
Δ = -18² - (4 * -4 * 10)
Δ = 324 - (4*-40)
Δ = 324 - (-160)
Δ = 484 Δ > 0
-4x2-18x+10=0
x = -b ∓ √Δ 2a
x' = 18 - √484 2*-4 = 18 - 22.0 -8 = -4.0 -8 = 0.5
x" = 18 + √484 2*-4 = 18 + 22.0 -8 = 40.0 -8 = -5.0
x' = 8.0
x" = -80.0
S = {x ∈ R / x' = 8.0, x" = -80.0 }