-4x2 -13x +12 = 0
ax2 bx c = 0
a = -4
b = -13
c = 12
Δ = b2-4ac
Δ = -13² - (4 * -4 * 12)
Δ = 169 - (4*-48)
Δ = 169 - (-192)
Δ = 361 Δ > 0
-4x2-13x+12=0
x = -b ∓ √Δ 2a
x' = 13 - √361 2*-4 = 13 - 19.0 -8 = -6.0 -8 = 0.75
x" = 13 + √361 2*-4 = 13 + 19.0 -8 = 32.0 -8 = -4.0
x' = 12.0
x" = -64.0
S = {x ∈ R / x' = 12.0, x" = -64.0 }