Question

CMR:
8⁷ - 2¹⁸ chia hết cho 14.

Answer 1

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

=>đpcm

Answer 2

8⁷-2¹⁸=(2³)⁷-2¹⁸=2²¹-2¹⁸=2¹⁷.(2⁴-2)=2¹⁷.14 chia hết cho 14

=> dpcm

Answer 3

8⁷ - 2¹⁸ = (2³)⁷ - 2¹⁸ = 2²¹ - 2¹⁸ = 2¹⁷(2⁴- 2) = 2¹⁷. 14 chia hết cho 14

Vậy 8⁷ - 2¹⁸ chia hết cho 14