Blackout1006

Chứng minh rằng:

$3^{n}\left ( C_{n}^{0}\textrm{}-\frac{1}{3}C_{n}^{1}\textrm{}+\frac{1}{3^{2}}C_{n}^{2}\textrm{}+...-\left ( -1 \right )^{n}\frac{1}{3^{n}}{}C_{n}^{n}\textrm{}. \right )$

chia hết cho 8 với $n\geq 3$