Sửa đề
\(x^3-7x^2+14x-8\)
\(=x^3-4x^2-3x^2+12x+2x-8\)
\(=x^2\left(x-4\right)-3x\left(x-4\right)+2\left(x-4\right)\)
\(=\left(x-4\right)\left(x^2-3x+2\right)\)
\(=\left(x-4\right)\left(x^2-2x-x+2\right)\)
\(=\left(x-4\right)\left[x\left(x-2\right)-\left(x-2\right)\right]\)
\(=\left(x-4\right)\left(x-2\right)\left(x-1\right)\)