Tại \(x=-3\) thì:
\(B=\left[-3^{2007}+3.\left(-3\right)^{2006}-1\right]^{2007}\)
\(\Rightarrow B=\left[-3^{2006}\left(-1+3\right)-1\right]^{2007}\)
\(\Rightarrow B=\left[-3^{2006}.2-1\right]^{2007}\)
Thay \(x=3\) vào B ta có:
\(B=\left[\left(-3\right)^{2007}+3.\left(-3\right)^{2006}-1\right]^{2007}\)
\(=\left[\left(-3\right)^{2007}+3^{2007}-1\right]^{2007}\)
\(=\left(-1\right)^{2007}=-1\)