Question

Numărul A = 1+2+2^2+2^11 se divide cu ......

2^2= 2 la puterea a doua ​

Answer 1

$\it A= 1+\underbrace{\it2+2^2+2^3+\ ...\ +2^{11}}_{nr.\ par} \Rightarrow A = nr.\ impar \Rightarrow A\not{\vdots} 2 \Rightarrow A\not{\vdots} 2^2$