Đáp án+Giải thích các bước giải:
`8) x^(10)+x^5+1`
`=x^(10)-x^9+x^9-x^8+x^8-x^7+x^7-x^6+x^6-x^5+x^5+x^5+x^4-x^4+x^3-x^3+x^2-x^2+x-x+1`
`=(x^(10)-x^9+x^7-x^6+x^5-x^3+x^2)+(x^9-x^8+x^6-x^5+x^3-x^2+x)+(x^2-x^7+x^5-x^4+x^2+x+1)`
`=x^2(x^8-x^7+x^5-x^4+x^2+x+1)+x(x^2-x^7+x^5-x^4+x^2+x+1)+(x^2-x^7+x^5-x^4+x^2+x+1)`
`=(x^2+x+1)(x^2-x^7+x^5-x^4+x^2+x+1)`
`11) 15x^2+7x-12 ->` Sửa `12x^2+7x-12`
`12x^2+7x-12`
`=12x^2-9x+16x-12`
`=(12x^2-9x)+(16x-12)`
`=3x(4x-3)+4(4x-3)`
`=(3x+4)(4x-3)`
