Question

[trí Hùng]

chứng minh rằng Cho A= 2+2^2+2^4+2^5+2^6+2^7+2^8+2^9+2^10 chia hết cho 3

Answer 1

[Phong Linh]

P=3+2^2(2+1)+2^4(2+1)+2^6(2+1)

=3(1+2^2+2^4+2^6)

=>đpcm