`a) 3x(2-8x) - 12x(1-2x)=6`

`6x - 24x^2 - 12x + 24x^2 = 6`

`-6x = 6`

`x=-1`

Vậy `x=-1`

`b) (8x+2)(1-3x) + (6x-1)(4x-10)=-50`

`8x - 24x^2 + 2 - 6x + 24x^2 - 60x - 4x + 10=-50`

`-62x + 12=-50`

`-62x = -62`

`x=1`

Vậy `x=1`

`c) (2x+1)(2x-3) - (4x+1)(x+2)=8`

`4x^2 - 4x - 3 - 4x^2 -9x -2=8`

`-13x - 5=8`

`-13x=13`

`x=-1`

Vậy `x=-1`

`d) (1-2x)(3x+1) + 3x(2x-1)=9`

`3x + 1 - 6x^2 - 2x + 6x^2 -3x=9`

`-2x +1=9`

`-2x=8`

`x=-4`

Vậy `x=-4`

`e) (x^2-4x+16)(x+4) - x(x+1)(x+2)+3x^2=0`

`x^3 + 4x^2 - 4x^2 - 16x + 16x + 64 - (x^2 +x)(x+2) + 3x^2=0`

`x^3 + 3x^2 + 64 - x^3 - 3x^3 - 2x =0`

`-2x+64=0`

`-2x=-64`

`x=32`

Vậy `x=32`