Question

aratati ca numarul x=2la puterea n+2+3ori2la puterea n+1 minus2n este divizibil cu 9,pentru n apartineN

Answer 1

[tex]x=2^{n+2}+3*2^{n+1}-2^n\\ x=2^n*2^2+3*2^n*2-2^n\\ x=2^n(2^2+3*2-1)\\ x=2^n(4+6-1)\\ x=2^n*9[/tex]