Question

[thị hà phương nguyễn]

chứng minh:\(2^{27}+2^{25}\)chia hết cho 5

Answer 1

[.]

Ta có : 2²⁷=2³.(2⁴)⁶=8.\(\left(\overline{...6}\right)\)=\(\overline{...8}\)

           2²⁵=2.(2⁴)⁶=2.\(\left(\overline{...6}\right)\)=\(\overline{...2}\)

\(\Rightarrow\)2²⁷+2²⁵=\(\left(\overline{...8}\right)+\left(\overline{...2}\right)=\overline{...0}⋮5\)

Vậy 2²⁷+2²⁵ \(⋮\)5.