Sửa đề: x=8
Khi x=8 thì x+1=9
\(x^{13}-9x^{12}+9x^{11}-9x^{10}+\cdots-9x^2+9x-2\)
\(=x^{13}-x^{12}\left(x+1\right)+x^{11}\left(x+1\right)-x^{10}\left(x+1\right)+\cdots-x^2\left(x+1\right)+x\left(x+1\right)-2\)
\(=x^{13}-x^{13}-x^{12}+x^{12}+x^{11}-x^{11}-x^{10}+\cdots-x^3-x^2+x^2+x-2\)
=x-2
=8-2
=6