Question

chứng minh 3¹⁵ + 3¹⁴ + 3¹³ chia hết cho 13

giúp mình với

Answer 1

\(3^{15}+3^{14}+3^{13}\)

\(=3^{13}\left(3^2+3+1\right)=3^{13}\cdot13⋮13\)

Answer 2

\(=3^{13}\left(3^2+3+1\right)=3^{13}\cdot13⋮13\)

Answer 3

\(3^{15}+3^{14}+3^{13}\)

\(=3^{13}\left(3^2+3+1\right)\)

\(=3^{13}\left(9+3+1\right)\)

\(=3^{13}.13\)⋮13

⇒\(3^{15}+3^{14}+3^{13}\)⋮13