Question

Chứng minh rằng:

8 mũ 7 - 2 mũ 18 chia hết cho 14

Answer 1

\(8^7-2^{18}=\left(2^3\right)^7-2^{18}=2^{21}-2^{18}=2^{17}\left(2^4-2\right)=2^{17}.14⋮14\)

Answer 2

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

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

\(=2^{18}\left(2^3-1\right)=2^{18}.7\)

\(=2^{17}.14⋮14\)

Answer 3

8^7 - 2^18 

=(2^3)^7-2^18

=2^21-2^18

=2^18.2^3-2^18.1

=2^18.8-2^18.1

=2^18.(8-1)

=2^18.7

=2^17.2^1.7

=2^17.2.7

=2^17.(2.7)

=2^17.14 chia hết cho 14