`7,`

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

`= x^3+8-x(x^2-1)`

`= x^3+8-x^3+x`

`= x+8`

`8,`

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

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

`= -x^3-8+x^3-16x`

`= -16x-8`

`9,`

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

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

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

`= x^6-1`

`10,`

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

`= (x^3-8)(x^3+8)`

`= x^6-64`

__________________________________________

HĐT dùng trong bài:

`@` `(A-B)(A+B)=A^2-B^2`

`@` `A^3+B^3=(A+B)(A^2-AB+B^2)`

`@` `A^3-B^3=(A-B)(A^2+AB+B^2)`

`#TD`