-12x2 +x +13 = 0
ax2 bx c = 0
a = -12
b = 1
c = 13
Δ = b2-4ac
Δ = ² - (4 * -12 * 13)
Δ = 1 - (4*-156)
Δ = 1 - (-624)
Δ = 625 Δ > 0
-12x2+x+13=0
x = -b ∓ √Δ 2a
x' = -1 - √625 2*-12 = -1 - 25.0 -24 = -26.0 -24 = 1.08333333333
x" = -1 + √625 2*-12 = -1 + 25.0 -24 = 24.0 -24 = -1.0
x' = 156.0
x" = -144.0
S = {x ∈ R / x' = 156.0, x" = -144.0 }