Question

a = 15 la puterea + 3la puterea n * 5la puterea n+1+ 3 la puterea n * 5 la puterea n+2 divizor 31

Answer 1

15^n +(3^n)*5^(n+1) +(3^n)*5^(n+2)=

(3*5)^n +(3^n)*5^(n+1) +(3^n)*5^(n+2)=
(3^n)*(5^n)(1+5+25)=31*(3^n)*(5^n)=m31 (m=multiplu)

A=m31 deci se divide cu 31