Làm tính chia (x^4-2x^3+2x-1):(x^2-1)

$x^4-2x^3+2x-1\\=(x^4-2x^3+x^2)+(-x^2+2x-1)\\=x^2(x^2-x+1)-(x^2-2x+1)\\=(x^2-x+1)(x^2-1)\\\to(x^2-x+1)(x^2-1)\vdots(x^2-1)\\\to(x^4-2x^3+2x-1):(x^2-1)=x^2-x+1(\text{ dư 0 })$