22x2 +23x -15 = 0
ax2 bx c = 0
a = 22
b = 23
c = -15
Δ = b2-4ac
Δ = 23² - (4 * 22 * -15)
Δ = 529 - (4*-330)
Δ = 529 - (-1320)
Δ = 1849 Δ > 0
22x2+23x-15=0
x = -b ∓ √Δ 2a
x' = -23 - √1849 2*22 = -23 - 43.0 44 = -66.0 44 = -1.5
x" = -23 + √1849 2*22 = -23 + 43.0 44 = 20.0 44 = 0.454545454545
x' = -726.0
x" = 220.0
S = {x ∈ R / x' = -726.0, x" = 220.0 }