-12x2 -5x +7 = 0
ax2 bx c = 0
a = -12
b = -5
c = 7
Δ = b2-4ac
Δ = -5² - (4 * -12 * 7)
Δ = 25 - (4*-84)
Δ = 25 - (-336)
Δ = 361 Δ > 0
-12x2-5x+7=0
x = -b ∓ √Δ 2a
x' = 5 - √361 2*-12 = 5 - 19.0 -24 = -14.0 -24 = 0.583333333333
x" = 5 + √361 2*-12 = 5 + 19.0 -24 = 24.0 -24 = -1.0
x' = 84.0
x" = -144.0
S = {x ∈ R / x' = 84.0, x" = -144.0 }