Question

Chứng minh:

(16^5 - 2^15 ) chia hết cho 31

Nhanh cho mìn nha!!!!!

Thank you .......

Answer 1

Ta có :

16⁵ - 2¹⁵ 

= ( 2⁴ )⁵ - 2¹⁵

= 2²⁰ - 2¹⁵

= 2¹⁵ . ( 2⁵ - 1 )

= 2¹⁵ . 31 \(⋮\)31

Vậy ...

Answer 2

ta có:16^5=(2^4)^5=2^20

=.2^20-2^15:.31

=>2^15x2^5-2^15:.31

=>2^15x(2^5-1):.31

=>2^15x31:.31

ta có:31:.31=>2^15:.31=>2^15x31:.31

=>16^5-2^15:.31