-12x2 +22x +20 = 0
ax2 bx c = 0
a = -12
b = 22
c = 20
Δ = b2-4ac
Δ = 22² - (4 * -12 * 20)
Δ = 484 - (4*-240)
Δ = 484 - (-960)
Δ = 1444 Δ > 0
-12x2+22x+20=0
x = -b ∓ √Δ 2a
x' = -22 - √1444 2*-12 = -22 - 38.0 -24 = -60.0 -24 = 2.5
x" = -22 + √1444 2*-12 = -22 + 38.0 -24 = 16.0 -24 = -0.666666666667
x' = 360.0
x" = -96.0
S = {x ∈ R / x' = 360.0, x" = -96.0 }