Đáp án+Giải thích các bước giải:
`d)x^3-3x^2+3x-1-y^3`
`=(x^3-3x^2+3x-1)-y^3`
`=(x-1)^3-y^3`
`=(x-1-y)[(x-1)^2+(x-1)y+y^2]`
`=(x-y-1)(x^2-2x+1+xy-y+y^2)`
`e)x^2(x-3)^2-(x-3)^2-x^2+1`
`=[x^2(x-3)^2-(x-3)^2]-(x^2-1)`
`=(x-3)^2 (x^2-1)-(x^2-1)`
`=(x^2-1)[(x-3)^2-1]`
`=(x-1)(x+1)(x-3-1)(x-3+1)`
`=(x-1)(x+1)(x-4)(x-2)`.
`f)x^3-2x^2+4x-8`
`=(x^3-2x^2)+(4x-8)`
`=x^2(x-2)+4(x-2)`
`=(x-2)(x^2+4)`
`g)(x+y)^3-(x-y)^3`
`=(x+y-x+y)[(x+y)^2+(x+y)(x-y)+(x-y)^2]`
`=2y(x^2+2xy+y^2+x^2-y^2+x^2-2xy+y^2)`
`=2y(3x^2+y^2)`
`h)2a^2(x+y+z)-4ab(x+y+z)+2b^2(x+y+z)`
`=2(x+y+z)(a^2-2ab+b^2)`
`=2(x+y+z)(a-b)^2`
