Помогите с примером x^2-6x-9=0

X²-6x-9=0

x²-6x+9-18=0

(x-3) ²=18

x-3=√18 x-3=-√18

x-3=3√2 x-3=-3√2

x=3√2+3 x=-3√2+3

x=3 (√2+1) x=3 (1-√2)

ll способ

x²-6x-9=0

D=36+36=72

x₁ = (6+√72) / 2 = (6+6√2) / 2 = (6 * (1+√2)) / 2=3 (1+√2)

x₂ = (6-6√2) / 2 = (6 * (1-√2)) / 2=3 (1-√2)