6B.

`1)8x^3 - 12x^2 + 6x - 1 = 0`

`(2x)^3 - 3.(2x)^2.1 + 3 . 2x . 1^2 - 1^3 = 0`

`(2x - 1)^3 = 0`

`2x - 1 = 0`

`2x = 1`

`x = 1/2`

Vậy `x = 1/2`

`2)x^3 - 6x^2 + 12x - 8 = 27`

`x^3 - 3 . x^2 . 2 + 3 . x. 2^2 - 2^3 = 27`

`(x - 2)^3 = 27`

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

`x - 2 = 3`

`x = 5`

Vậy `x = 5`

`3)x^2 - 8x + 16 = 5(4 - x)^3`

`(x - 4)^2 = 5(4 - x)^3`

`(x - 4)^2 = -5(x - 4)^3`

`(x - 4)^2 + 5(x - 4)^3 = 0`

`(x - 4)^2.(1 + 5(x - 4)) = 0`

`(x - 4)^2.(5x - 19) = 0`

`(x - 4)^2 = 0` hoặc `5x - 19 = 0`

`x = 4` hoặc `x = 19/5`

Vậy `x \in{4 ; 19/5}`

`4)(2 - x)^3 = 6x(x - 2)`

`-(x - 2)^3 = 6x(x - 2)`

`(x - 2)^3 + 6x(x - 2) = 0`

`(x - 2).((x - 2)^2 + 6x) = 0`

`(x - 2).(x^2 + 2x + 4) = 0`

`x - 2 = 0` hoặc `x^2 + 2x + 4 = 0`

Vì `x^2 + 2x + 4 = (x + 1)^2 + 3 > 0 AA x`

`=> x - 2 = 0`

`x = 2`

Vậy `x = 2`

`5)(x + 1)^3 - (x - 1)^3 - 6(x - 1)^2 = -10`

`x^3 + 3x^2 + 3x + 1 - x^3 + 3x^2 - 3x + 1 - 6(x^2 - 2x + 1) = -10`

`x^3 + 3x^2 + 3x + 1 - x^3 + 3x^2 - 3x + 1 - 6x^2 + 12x - 6 = -10`

`12x - 4 = -10`

`12x = -6`

`x = -1/2`

Vậy `x = -1/2`

`6)(3 - x)^3 - (x + 3)^3 = 36x^2 - 54x`

`27 - 27x + 9x^2 - x^3 - (x^3 + 9x^2 + 27x + 27) = 36x^2 - 54x`

`27 - 27x + 9x^2 - x^3 - x^3 - 9x^2 - 27x - 27 = 36x^2 - 54x`

`-2x^3 - 54x = 36x^2 - 54x`

`-2x^3 - 36x^2 =0`

`-2x^2.(x + 18) = 0`

`x^2 = 0` hoặc `x + 18 = 0`

`x =0` hoặc `x = -18`

Vậy `x in{ 0 ;-18}`