Giúp mình với ạ mình cảm ơn

`a)x^2+4x+3`

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

`=x(x+3)+(x+3)`

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

`b)x^2-y^2+4-4x`

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

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

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

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

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

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

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

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

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

`d)-x-y^2+x^2-y`

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

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

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

`e)(a^2+1)^2-4a^2`

`=(a^2+1)^2-(2a)^2`

`=(a^2-2a+1)(a^2+2a+1)`

`=(a-1)^2(a+1)^2`

`f)5x^3-5x^2y-10x^2+10xy`

`=5x^2(x-y)-10x(x-y)`

`=(x-y)(5x^2-10x)`

`=5x(x-y)(x-2)`