-6x2 -x +7 = 0
ax2 bx c = 0
a = -6
b = -1
c = 7
Δ = b2-4ac
Δ = -² - (4 * -6 * 7)
Δ = 1 - (4*-42)
Δ = 1 - (-168)
Δ = 169 Δ > 0
-6x2-x+7=0
x = -b ∓ √Δ 2a
x' = 1 - √169 2*-6 = 1 - 13.0 -12 = -12.0 -12 = 1.0
x" = 1 + √169 2*-6 = 1 + 13.0 -12 = 14.0 -12 = -1.16666666667
x' = 36.0
x" = -42.0
S = {x ∈ R / x' = 36.0, x" = -42.0 }