5x2 +17x -12 = 0
ax2 bx c = 0
a = 5
b = 17
c = -12
Δ = b2-4ac
Δ = 17² - (4 * 5 * -12)
Δ = 289 - (4*-60)
Δ = 289 - (-240)
Δ = 529 Δ > 0
5x2+17x-12=0
x = -b ∓ √Δ 2a
x' = -17 - √529 2*5 = -17 - 23.0 10 = -40.0 10 = -4.0
x" = -17 + √529 2*5 = -17 + 23.0 10 = 6.0 10 = 0.6
x' = -100.0
x" = 15.0
S = {x ∈ R / x' = -100.0, x" = 15.0 }