Răspuns:

răspunsul este egal cu 36

Verified answer

a)

[tex]\it a=2\cdot2^{n+1}\cdot5^{n+1}\cdot25+2^{n+1}\cdot5^{n+1}\cdot125=2^{n+1}\cdot5^{n+1}\cdot(50+125)=\\ \\ \\ =2^{n+1}\cdot5^{n+1}\cdot175=2^{n+1}\cdot5^{n+1}\cdot5^2\cdot7=2^{n+1}\cdot5^{n+3}\cdot7[/tex]

b)

[tex]\it a=2^{n+1}\cdot5^{n+1}\cdot175=2^{n}\cdot5^{n+1}\cdot350=2^{n}\cdot5^{n+1}\cdot5\cdot70\in M_{70} \Rightarrow 70\Big| a[/tex]