Phân tích đa thức thành nhân từ: x^3 - x^2 + x + 1?

Bài 1: Phân tích đa thức thành nhân tử
${\mathbf{x}}^{\mathbf{3}}\mathbf{ }\mathbf{-}\mathbf{ }{\mathbf{x}}^{\mathbf{2}}\mathbf{ }\mathbf{+}\mathbf{ }\mathbf{x}\mathbf{ }\mathbf{+}\mathbf{ }\mathbf{1}$
Bài 2: $\mathit{G}\mathit{T}\mathit{:}\mathit{ }\mathit{∆}\mathit{A}\mathit{B}\mathit{C}\mathit{,}\mathit{ }\mathit{A}\mathit{B}\mathit{=}\mathit{A}\mathit{C}\mathit{=}\mathit{3}\mathit{c}\mathit{m}$
$\mathit{ }\mathit{ }\mathit{ }\mathit{ }\mathit{ }\mathit{ }\mathit{ }\mathit{ }\mathit{M}\mathit{\in }\mathit{B}\mathit{C}\mathit{,}\mathit{ }\mathit{M}\mathit{D}\mathit{\parallel }\mathit{A}\mathit{C}\mathit{,}\mathit{ }\mathit{M}\mathit{E}\mathit{\parallel }\mathit{A}\mathit{B}\mathit{ }\mathit{(}\mathit{D}\mathit{\in }\mathit{A}\mathit{B}\mathit{,}\mathit{ }\mathit{E}\mathit{\in }\mathit{A}\mathit{C}\mathit{)}$
           $\mathit{K}\mathit{L}\mathit{:}\mathit{ }\mathit{T}\mathit{í}\mathit{n}\mathit{h}\mathit{ }\mathit{c}\mathit{h}\mathit{u}\mathit{ }\mathit{v}\mathit{i}\mathit{ }\mathit{t}\mathit{ứ}\mathit{ }\mathit{g}\mathit{i}\mathit{á}\mathit{c}\mathit{ }\mathit{A}\mathit{D}\mathit{M}\mathit{E}$