Sa vad daca pot sa descifrez
[tex]N=2^n\cdot5^{n+1}+2^{n+1}\cdot5^n+2^{n+1}+5^{n+1} \\ \\ =2^n\cdot5^n\cdot5+2^n\cdot2\cdot5^n+2^n\cdot2\cdot5^n\cdot5 \\ \\ =10^n\cdot5+10^n\cdot2+10^n\cdot10 \\ \\ =10^n(5+2+10) \\ \\ =10^n\cdot17 \\ \\ =10^{n-1}\cdot10\cdot17 \\ \\ =10^{n-1}\cdot170 \\ \\ n\in\mathbb{N}*\Rightarrow n-1\in\mathbb{N}\Rightarrow N\vdots170[/tex]
