-12x2 +7x +5 = 0
ax2 bx c = 0
a = -12
b = 7
c = 5
Δ = b2-4ac
Δ = 7² - (4 * -12 * 5)
Δ = 49 - (4*-60)
Δ = 49 - (-240)
Δ = 289 Δ > 0
-12x2+7x+5=0
x = -b ∓ √Δ 2a
x' = -7 - √289 2*-12 = -7 - 17.0 -24 = -24.0 -24 = 1.0
x" = -7 + √289 2*-12 = -7 + 17.0 -24 = 10.0 -24 = -0.416666666667
x' = 144.0
x" = -60.0
S = {x ∈ R / x' = 144.0, x" = -60.0 }