-9x2 +22x -8 = 0
ax2 bx c = 0
a = -9
b = 22
c = -8
Δ = b2-4ac
Δ = 22² - (4 * -9 * -8)
Δ = 484 - (4*72)
Δ = 484 - (288)
Δ = 196 Δ > 0
-9x2+22x-8=0
x = -b ∓ √Δ 2a
x' = -22 - √196 2*-9 = -22 - 14.0 -18 = -36.0 -18 = 2.0
x" = -22 + √196 2*-9 = -22 + 14.0 -18 = -8.0 -18 = 0.444444444444
x' = 162.0
x" = 36.0
S = {x ∈ R / x' = 162.0, x" = 36.0 }