Question

Giải giúp mk bài này với. ai nhanh mk tick cho.

a) \(7^8+7^9+7^{10}⋮57\)

b)\(10^{10}-10^9-10^8⋮89\)

c) \(8^{10}-8^9-8^8⋮55\)

d) \(81^7-27^9-9^{13}⋮45\)

Answer 1

a) \(7^8+7^9+7^{10}\)

\(=7^8\left(1+7+7^2\right)\)

\(=7^8.57⋮57\)

b) \(10^{10}-10^9-10^8=10^8\left(10^2-10-1\right)\)

\(=10^8⋮89\)

Answer 2

c) \(8^{10}-8^9-8^8\)

\(=8^8\left(8^2-8-1\right)\)

\(=8^8.55⋮55\)

d) \(81^7-27^9-9^{13}\)

\(=2^{28}-3^{27}-3^{26}\)

\(=3^{26}\left(3^2-3-1\right)\)

\(=3^{29}.5=3^{27}.45⋮45\)