$x^4-10x^2+11x-10\\=x^4+x^3-x^3-10x^2-x^2+x^2+10x+x-10\\=(x^4+x^3-10x^2)-(x^3+x^2-10x)+(x^2+x-10)\\=x^2(x^2+x-10)-x(x^2+x-10)+(x^2+x-10)\\=(x^2-x+1)(x^2+x-10)\\=(x^2-x+1)\left(x^2+2.x.\dfrac{1}{2}+\dfrac{1}{4}-\dfrac{41}{4}\right)\\=(x^2-x+1)\left[\left(x+\dfrac{1}{2}\right)^2-\left(\dfrac{\sqrt{41}}{2}\right)^2\right]\\=(x^2-x+1)\left(x-\dfrac{-1+\sqrt{41}}{2}\right)\left(x-\dfrac{-1-\sqrt{41}}{2}\right)$
Vậy $x^4-10x^2+11x-10=(x^2-x+1)\left(x-\dfrac{-1+\sqrt{41}}{2}\right)\left(x-\dfrac{-1-\sqrt{41}}{2}\right)$
