15x2 +22x -16 = 0
ax2 bx c = 0
a = 15
b = 22
c = -16
Δ = b2-4ac
Δ = 22² - (4 * 15 * -16)
Δ = 484 - (4*-240)
Δ = 484 - (-960)
Δ = 1444 Δ > 0
15x2+22x-16=0
x = -b ∓ √Δ 2a
x' = -22 - √1444 2*15 = -22 - 38.0 30 = -60.0 30 = -2.0
x" = -22 + √1444 2*15 = -22 + 38.0 30 = 16.0 30 = 0.533333333333
x' = -450.0
x" = 120.0
S = {x ∈ R / x' = -450.0, x" = 120.0 }