Ta có: \(A=1+2+2^2+2^3+....+2^{1975}\)
\(\Rightarrow2A=2.\left(1+2^2+2^3+....+2^{1975}\right)\)
\(\Rightarrow2A=2+2^2+2^3+2^4+....+2^{1976}\)
\(\Rightarrow2A-A=\left(2+2^2+2^3+2^4+....+2^{1976}\right)-\left(1+2+2^2+2^3+....+2^{1975}\right)\)
\(\Rightarrow A=2^{1976}-2\)
Mà \(B=2^{1976}\). Nên A < B
Vậy A < B