-12x2 -11x +15 = 0
ax2 bx c = 0
a = -12
b = -11
c = 15
Δ = b2-4ac
Δ = -11² - (4 * -12 * 15)
Δ = 121 - (4*-180)
Δ = 121 - (-720)
Δ = 841 Δ > 0
-12x2-11x+15=0
x = -b ∓ √Δ 2a
x' = 11 - √841 2*-12 = 11 - 29.0 -24 = -18.0 -24 = 0.75
x" = 11 + √841 2*-12 = 11 + 29.0 -24 = 40.0 -24 = -1.66666666667
x' = 108.0
x" = -240.0
S = {x ∈ R / x' = 108.0, x" = -240.0 }