Question

Chung to M=2+2^2+2^3+2^4+...+2^98 chia hét cho 3

                         Mình cần gấp nha hurry up please 😘😘

 

Answer 1

\(A=2+2^2+2^3+...+2^{98}\)

\(A=\left(2+2^2\right)+\left(2^3+2^4\right)+...+\left(2^{97}+2^{98}\right)\)

\(A=2\left(1+2\right)+2^3\left(1+2\right)+...+2^{97}\left(1+2\right)\)

\(A=2\cdot3+2^3\cdot3+...+2^{97}\cdot3\)

\(A=3\cdot\left(2+2^3+...+2^{97}\right)⋮3\left(đpcm\right)\)