Question

1+2+2 la puterea 2 + 2 la puterea 3 + ...+ 2 la puterea 6
Ce formula trebuie aplicata? Multumesc.

Answer 1

$2^0+2^1+2^2+...+2^n= 2^{n+1}-1$

$1+2+2^2+2^3+...+2^6=2^0+2^1+2^2+...+2^6=2^7-1=128-1$

Answer 2

1+2+2^2+2^3+.....+2^6=2^0+2^1+2^2+2^3+2^3(2+2^2+2^3)=1+2+4+8+8(2+4+8)=15+8×14=15+112=127. (Nu exista nici o formula pt puteri la adunare, poti doar sa dai factor comun.)