Question

Cho A=1+3+3²+3³+....3⁹⁸.hãy chứng tỏ rằng A chia hết cho 13

mong mọi người giúp đỡ mik nha TIM TIM

 

Answer 1

\(A=\left(1+3+3^2\right)+3^3\left(1+3+3^2\right)+...+3^{96}\left(1+3+3^2\right)\)

\(=13+3^3.13+...+3^{96}.13\)

\(=13\left(1+3^3+...+3^{96}\right)⋮13\)

Answer 2

\(A=\left(1+3+3^2\right)+\left(3^3+3^4+3^5\right)+...+\left(3^{96}+3^{97}+3^{98}\right)\\ A=\left(1+3+3^2\right)+3^3\left(1+3+3^2\right)+...+3^{96}\left(1+3+3^2\right)\\ A=\left(1+3+3^2\right)\left(1+3^3+...+3^{96}\right)\\ A=13\left(1+3^3+...+3^{96}\right)⋮13\)

Answer 3

mn ơi mong mọi người trả lời câu hỏi giúp mik với ạ 

Answer 4

A=(1+3+32)+33(1+3+32)+...+396(1+3+32)

 

=13+33.13+...+396.13

 

=13(1+33+...+396)⋮13

Answer 5