Question

Chứng minh

\(\left(8^7-2^{18}\right)⋮14\)

Cần gấp nhé

Answer 1

\(8^7-2^{18}\)

\(=\left(2^3\right)^7-2^{18}\)

\(=2^{21}-2^{18}\)

\(=2^{17}\left(2^4-2\right)\)

\(=2^{17}\cdot14⋮14\left(đpcm\right)\)

Answer 2

Ta có 8=2^3

\(\Rightarrow8^7-2^{18}=2^{3^7}-2^{18}\\ =2^{21}-2^{18}\\ =2^{17}\left(2^4-2\right)\)

\(=2^{17}.14⋮14\)

\(\Rightarrowđpcm\)