-6x2 -13x +19 = 0
ax2 bx c = 0
a = -6
b = -13
c = 19
Δ = b2-4ac
Δ = -13² - (4 * -6 * 19)
Δ = 169 - (4*-114)
Δ = 169 - (-456)
Δ = 625 Δ > 0
-6x2-13x+19=0
x = -b ∓ √Δ 2a
x' = 13 - √625 2*-6 = 13 - 25.0 -12 = -12.0 -12 = 1.0
x" = 13 + √625 2*-6 = 13 + 25.0 -12 = 38.0 -12 = -3.16666666667
x' = 36.0
x" = -114.0
S = {x ∈ R / x' = 36.0, x" = -114.0 }