5x2 -13x +6 = 0
ax2 bx c = 0
a = 5
b = -13
c = 6
Δ = b2-4ac
Δ = -13² - (4 * 5 * 6)
Δ = 169 - (4*30)
Δ = 169 - (120)
Δ = 49 Δ > 0
5x2-13x+6=0
x = -b ∓ √Δ 2a
x' = 13 - √49 2*5 = 13 - 7.0 10 = 6.0 10 = 0.6
x" = 13 + √49 2*5 = 13 + 7.0 10 = 20.0 10 = 2.0
x' = 15.0
x" = 50.0
S = {x ∈ R / x' = 15.0, x" = 50.0 }