TƯƠNG TỰ CÁC BÀI TRONG NÂNG CAO PHÁT TRIỂN 8
\(x^4-6x^3+7x^2-6x+1\)
\(=x^4+x^2+1-6x^3+6x^2-6x\)
\(=\left(x^2+1\right)^2-x^2-6x\left(x^2-x+1\right)\)
\(=\left(x^2+x+1\right)\left(x^2-x+1\right)-6x\left(x^2-x+1\right)\)
\(=\left(x^2-x+1\right)\left(x^2+x+1-6x\right)\)
\(=\left(x^2-x+1\right)\left(x^2-5x+1\right)\)