Răspuns:
1+2⁰+2¹+2²+...+2¹⁹⁶⁸
Notezi cu S=2⁰+2¹+2²+...+2¹⁹⁶⁸=
S=1+2¹+2²+...+2¹⁹⁶⁸
2S=2(1+2¹+2²+....+2¹⁹⁶⁸)=
2+2²+2³+....+2¹⁹⁶⁸+2¹⁹⁶⁹
2S-S=(2+2²+2³+...+2¹⁹⁶⁸+2¹⁹⁶⁹)-(1+2¹+2²+,..+2¹⁹⁶⁸)=
2+2²+2³+...+2¹⁹⁶⁸+2¹⁹⁶⁹-1-2¹-2²-...-2¹⁹⁶⁸=
2¹⁹⁶⁹-1=S
S+1=2¹⁹⁶⁹-1+1=2¹⁹⁶⁹
Explicație pas cu pas: