Question

2^la n+3+2^la n+2 -2^ la n+1 se divide cu10

Answer 1

$2^{n+3}+2^{n+2}-2^{n+1}=2^n\cdot 8+2^n\cdot 4-2^n\cdot 2=2^n(8+4-2)=\\=2^n\cdot 10\ \vdots \ 10$