-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 = -40.0 -8 = 5.0
x" = -18 + √484 2*-4 = -18 + 22.0 -8 = 4.0 -8 = -0.5
x' = 80.0
x" = -8.0
S = {x ∈ R / x' = 80.0, x" = -8.0 }