\(x^8y^8+x^4y^4+1\)
\(=\left(x^4y^4\right)^2+2x^4y^4+1-x^4y^4\)
\(=\left(x^4y^4+1\right)^2-\left(x^2y^2\right)^2\)
\(=\left(x^4y^4-x^2y^2+1\right)\left(x^4y^4+x^2y^2+1\right)\)
\(=\left(x^4y^4-x^2y^2+1\right)\left[\left(x^2y^2+1\right)^2-\left(xy\right)^2\right]\)
\(=\left(x^4y^4-x^2y^2+1\right)\left(x^2y^2-xy+1\right)\left(x^2y^2+xy+1\right)\)
Chúc bạn học tốt.