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 = -22.0 44 = -0.5
x" = 15 + √1369 2*22 = 15 + 37.0 44 = 52.0 44 = 1.18181818182
x' = -242.0
x" = 572.0
S = {x ∈ R / x' = -242.0, x" = 572.0 }