`#AkaShi`
`c)`
`x^8+x+1`
`=x^8-x^2+x^2+x+1`
`=x^2(x^6-1)+(x^2+x+1)`
`=x^2(x^3-1)(x^3+1)+(x^2+x+1)`
`=x^2(x^3+1)(x-1)(x^2+x+1)+(x^2+x+1)`
`=(x^2+x+1)[x^2(x^3+1)(x-1)+1]`
`(x^2+x+1)[(x^5+x^2)(x-1)+1]`
`=(x^2+x+1)(x^6-x^5+x^3-x^2+1)`
`\text{____________________________________________}`
`d)`
`x^8+x^7+1`
`=x^8+x^7+x^6-x^6+1`
`=x^6(x^2+x+1)-(x^6-1)`
`=x^6(x^2+x+1)-(x^3-1)(x^3+1)`
`=x^6(x^2+x+1)-(x-1)(x^2+x+1)(x^3+1)`
`=(x^2+x+1)[x^6-(x-1)(x^3+1)]`
`=(x^2+x+1)[x^6(x^4+x-x^3-1)]`
`=(x^2+x+1)(x^6-x^4-x+x^3+1)`
`\text{____________________________________________}`
`**` Đáp án:
`a) x^8+x+1=(x^2+x+1)(x^6-x^5+x^3-x^2+1)``
`b) x^8+x^7+1=(x^2+x+1)(x^6-x^4-x+x^3+1)``
