18x2 +19x -14 = 0
ax2 bx c = 0
a = 18
b = 19
c = -14
Δ = b2-4ac
Δ = 19² - (4 * 18 * -14)
Δ = 361 - (4*-252)
Δ = 361 - (-1008)
Δ = 1369 Δ > 0
18x2+19x-14=0
x = -b ∓ √Δ 2a
x' = -19 - √1369 2*18 = -19 - 37.0 36 = -56.0 36 = -1.55555555556
x" = -19 + √1369 2*18 = -19 + 37.0 36 = 18.0 36 = 0.5
x' = -504.0
x" = 162.0
S = {x ∈ R / x' = -504.0, x" = 162.0 }