Question

Cho A=1+2+2^2+.....+2^2008 B=2009 Tính B-A

Answer 1

\(2A=2+2^2+2^3+...+2^{2009}\)

\(2A-A=2-2+2^2-2^2+...+2^{2009}-1\)

\(A=2^{2009}-1\)

\(B-A=2^{2009}-2^{2009}+1=1\)

Vậy....

Answer 2

\(2A=2+2^2+2^3+...+2^{2009}\)

\(2A-A=2-2+2^2-2^2+...+2^{2009}-1\)

\(A=2^{2009}-1\)

\(B-A=2^{2009}-2^{2009}+1=1\)

Vậy....