Giải:
Thay \(2012=x+1\) vào biểu thức ta có:
\(\Rightarrow B=x^{2011}-\left(x+1\right).x^{2010}+\left(x+1\right).x^{2009}-...-\left(x+1\right).x^2+\left(x+1\right).x-1\)
\(=x^{2011}-x^{2011}-x^{2010}+x^{2010}+x^{2009}-...-x^2+x^2+x-1\)
\(=x-1\)
\(\Rightarrow B=2011-1=2010\)
Vậy \(B=2010\)