Question

aratati ca B =( 5^n+2 +2 x 5^n+1 - 5^n) :7
: -este divizibil

Answer 1

[tex]B=5^n\cdot 5^2+2\cdot 5^n\cdot 5^1-5^n\\ B=5^n(25+10-1)\\ B=5^n\cdot14=7\cdot2\cdot 5^n\\ B\vdots7[/tex]