giúp ý b,c,d vs thankkk

Answer:

$\color{red}{b)}$

`-8x^3 + 12x - 6x + 1`

`= -(8x^3 + 12x - 6x + 1)`

`= -[(2x)^3 - 3.(2x)^2.1 + 3.2x.1^2 - 1^3]`

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

$\color{red}{c)}$

`x^3 - 3/2x^2y + 3/4xy^2 - 1/8y^3`

`= [x^3 - 3.x^2.1/2y + 3.x.(1/2y)^2 - (1/2y)^3]`

`= (x-1/2y)^3`

$\color{red}{d)}$

`(x-y)^3 + 6(x-y)^3 + 12(x-y)+8`

`= [(x-y)^3 + 3.(x-y)^2.2 + 3.(x-y).2^2 + 2^3]`

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

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