Question

Viết lại dưới dạng lập phương     a, -x^3+3x^2-3x+1   b, x^3+x^2+1/3x+1/27 c,x^6-3x^4y+3x^2y^2-y^3

Answer 1

`a)-x^3+3x^2-3x+1`

`=-(x^2-3x^2+3x-1)`

`=-(x-1)^3`

______________________________________________

`b)x^3+x^2+1/3x+1/27`

`=x^3+3.x^2. 1/3+3.x. (1/3)^2+(1/3)^3`

`=(x+1/3)^3`

______________________________________________

`c)x^6-3x^4y+3x^2y^2-y^3`

`=(x^2)^3-3(x^2)^2y+3x^2y^2-y^3`

`=(x^2-y)^3`

Answer 2

`a, -(x-3)^3`

`b, (x+1/3)^3`

`c, (x^2-y)^3`