Question

Cho B = 4^1 + 4^2 + 4^3 + ........... + 4^300 . Chứng minh rằng B chia hết cho 5

Answer 1

\(B=4+4^2+4^3+...+4^{300}\)

\(B=\left(4+4^2\right)+\left(4^3+4^4\right)+...+\left(4^{299}+4^{300}\right)\)

\(B=5.4+5.4^3+...+5.4^{299}\)

\(B=5\left(4+4^3+4^5+...+4^{299}\right)\)

\(\Rightarrow B⋮5\)

Answer 2

\(\sqrt{\sqrt[]{}\sqrt[]{}\begin{matrix}&\\&\\&\end{matrix}}\)

Answer 3

Vb 

Answer 4

 B v. C. 😶‍🌫️😅