Đáp án:
`x^3+3x^2+3x+1-27z^3=(x-3z+1)(x^2+2x+1+3xz+3z+9z^2)`
`x^4+x^3+x+1=(x+1)^2(x^2-x+1)`
`x^2-x^3-x^2+1=(1-x)(x^2+x+1)`
Giải thích các bước giải:
`x^3+3x^2+3x+1-27z^3=(x+1)^3-(9z)^3=(x+1-3z)[(x+1)^2+(x+1)3z+9z^2]`
`=(x-3z+1)(x^2+2x+1+3xz+3z+9z^2)`
`x^4+x^3+x+1=x^3(x+1)+(x+1)=(x+1)(x^3+1)=(x+1)^2(x^2-x+1)`
`x^2-x^3-x^2+1=-x^3+1=-(x^3-1)=-(x-1)(x^2+x+1)=(1-x)(x^2+x+1)`