18x2 -17x +4 = 0
ax2 bx c = 0
a = 18
b = -17
c = 4
Δ = b2-4ac
Δ = -17² - (4 * 18 * 4)
Δ = 289 - (4*72)
Δ = 289 - (288)
Δ = 1 Δ > 0
18x2-17x+4=0
x = -b ∓ √Δ 2a
x' = 17 - √1 2*18 = 17 - 1.0 36 = 16.0 36 = 0.444444444444
x" = 17 + √1 2*18 = 17 + 1.0 36 = 18.0 36 = 0.5
x' = 144.0
x" = 162.0
S = {x ∈ R / x' = 144.0, x" = 162.0 }