giúp mk vs ạ mk cảm ơn trc

Đáp án+Giải thích các bước giải:

`a.`

`ax^2-2bxy+2bx^2-axy`

`=ax^2+2bx^2 -axy-2bxy`

`=(a+2b)x^2 -xy(a+2b)`

`=(a+2b)(x^2-xy)`

`=x(a+2b)(x-y)`

`b.`

`8-x^2+2x`

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

`=9-(x-1)^2`

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

`=(4-x)(2+x)`

`c.`

`x^2+2x-4y^2+8y-3`

`=x^2+2x+1-4y^2+8y-4`

`=(x+1)^2-4(y-1)^2`

`=(x+1+2y-2)(x+1-2y+2)`

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

`d.`

`x^4-5x^3+20x-16`

`=x^4-16-5x^3+20x`

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

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

`=(x^2-4)(x-1)(x-4)`