\(=(x^2-x+1)(x^3+x^2-1)\)
\(=(x^2-x+1)(x^3-x-1)\)
\(=(x^2+x+1)(x^5-x^4+x^2-x+1)\)
\(=(x^2+x+1)(x^7-x+1)\)
\(x^5+x-1\)
\(=x^5+x^4-x^4+x^3-x^3+x^2-x^2+x-1\)
\(=\left(x^5-x^4+x^3\right)+\left(x^4-x^3+x^2\right)-\left(x^2-x+1\right)\)
\(=x^3\left(x^2-x+1\right)+x^2\left(x^2-x+1\right)-\left(x^2-x+1\right)\)
\(=\left(x^2-x+1\right)\left(x^3+x^2-1\right)\)
\(x^5-x^4-1\)
\(=x^5-x^4-x^3+x^3-x^2+x^2-x+x-1\)
\(=\left(x^5-x^3-x^2\right)-\left(x^4-x^2-x\right)+\left(x^3-x-1\right)\)
\(=x^2\left(x^3-x-1\right)-x\left(x^3-x-1\right)+\left(x^3-x-1\right)\)
\(=\left(x^3-x-1\right)\left(x^2-x+1\right)\)
Các bài còn lại tương tự nha . Chúc bạn học tốt
