Question

cho A = 1+2+2^2+....+2^2023+262024. chứng tỏ Achia hết cho 7 cứu tuiii nhanh giúp mình nha làm ơn

Answer 1

help meeee

 

Answer 2

\(A=1+2+2^2+...+2^{2024}\)

\(=\left(1+2+2^2\right)+\left(2^3+2^4+2^5\right)+...+\left(2^{2022}+2^{2023}+2^{2024}\right)\)

\(=\left(1+2+2^2\right)+2^3\left(1+2+2^2\right)+...+2^{2022}\left(1+2+2^2\right)\)

\(=7\cdot\left(1+2^3+...+2^{2022}\right)⋮7\)

Answer 3