\(A=1+2+2^2+...+2^{2009}\)
\(\Rightarrow2A=2+2^2+2^3+...+2^{2010}\)
\(\Rightarrow2A-A=2+2^2+2^3+...+2^{2010}-\left(1+2+2^2+2^3+...+2^{2009}\right)\)
\(\Rightarrow A=2+2^2+2^3+...+2^{2010}-1-2-2^2-2^3-...-2^{2009}\)
\(\Rightarrow2^{2010}-1\)
\(\Rightarrow B-A=2^{2010}-\left(2^{2010}-1\right)\)
\(\Rightarrow2^{2010}-2^{2010}+1\)
\(\Rightarrow1\)
\(\Rightarrow B-A=1\)