22x2 +15x -13 = 0
ax2 bx c = 0
a = 22
b = 15
c = -13
Δ = b2-4ac
Δ = 15² - (4 * 22 * -13)
Δ = 225 - (4*-286)
Δ = 225 - (-1144)
Δ = 1369 Δ > 0
22x2+15x-13=0
x = -b ∓ √Δ 2a
x' = -15 - √1369 2*22 = -15 - 37.0 44 = -52.0 44 = -1.18181818182
x" = -15 + √1369 2*22 = -15 + 37.0 44 = 22.0 44 = 0.5
x' = -572.0
x" = 242.0
S = {x ∈ R / x' = -572.0, x" = 242.0 }