Giải thích các bước giải:
$b. x^{10}-2006x^{9}+2006x^{8}-2006x^{7}+2006x^{6}+...-2006x+2006\\
=(2006x^{10}-2006x^{9}+2006x^{8}-2006x^{7}+2006x^{6}+...-2006x+2006)-2005x^{10}\\
=2006(x^{10}-x^{9}+x^{8}-x^{7}+x^{6}+...-x+1)-2005x^{10}\\
=2006\dfrac{x^{11}+1}{x+1}-2005x^{10}\\
=2006\dfrac{2005^{11}+1}{2006}-2005^{11}\\
=2005^{11}+1-2005^{11}\\
=1$