Giải cho mình với ạ

`1. x^2 - 25= (x - 5)(x + 5)`

`2. 9x^2 - 1/16y^2= (3x)^2 - (1/4y)^2= (3x - 1/4y)(3x + 1/4y)`

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

`4. (2x - 5)^2 - 64= (2x - 5)^2 - 8^2= (2x - 5 - 8)(2x - 5 + 8)= (2x - 13)(2x + 3)`

`5. 81 - (3x + 2)^2= 9^2 - (3x + 2)^2= (9 - (3x + 2))(9 + (3x + 2))= (7 - 3x)(11 + 3x)`

`6. 9(x - 5y)^2 - 16(x + y)^2= (3(x - 5y))^2 - (4(x + y))^2= (3(x - 5y) - 4(x + y))(3(x - 5y) + 4(x + y))= (3x - 15y - 4x - 4y)(3x - 15y + 4x + 4y)= (-x - 19y)(7x - 11y)`

`7. x^3 - 8= x^3 - 2^3= (x - 2)(x^2 + 2x + 4)`

`8. 27x^3 + 125y^3= (3x)^3 + (5y)^3= (3x + 5y)((3x)^2 - 3x*5y + (5y)^2)= (3x + 5y)(9x^2 - 15xy + 25y^2)`

`9. x^6 + 216= (x^2)^3 + 6^3= (x^2 + 6)((x^2)^2 - 6x^2 + 36)= (x^2 + 6)(x^4 - 6x^2 + 36)`

`10. x^2 + 8x + 16= x^2 + 4x + 4x + 16 = (x + 4)^2`

`11. 9x^2 - 12xy + 4y^2= (3x)^2 - 2*3x^2y + (2y)^2= (3x - 2y)^2`

`12. -25x^2y^2 + 10xy - 1= -(5xy)^2 + 25xy1 - 1^2= -(5xy - 1)^2`

`13. x^3 - 6x^2 + 12x - 8= (x - 2)(x^2 - 4x + 4)= (x - 2)(x - 2)^2= (x - 2)^3`

`14. 8x^3 + 12x^2y + 6xy^2 + y^3= (2x + y)^3`

`17. x^2 - 9= (x - 3)(x + 3)`

`18. 4x^2 - 25= (2x)^2 - 5^2= (2x - 5)(2x + 5)`

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

`20. 9x^2 + 6xy + y^2= (3x)^2 + 2*3xy + y^2= (3x + y)^2`

`21. 6x - 9 - x^2= -x^2 + 6x - 9= -(x^2 - 6x + 9)= -(x - 3)^2`

`22. x^2 + 4y^2 + 4xy= x^2 + 4xy + 4y^2= (x + 2y)^2`

`23. (x + y)^2 - (x - y)^2= ((x + y) - (x - y))((x + y) + (x - y))= (2y)(2x)= 4xy`

`24. (x + y + z)^2 - 4z^2= ((x + y + z) - 2z)((x + y + z) + 2z)= (x + y - z)(x + y + 3z)`

`25. (3x + 1)^2 - (x + 1)^2= ((3x + 1) - (x + 1))((3x + 1) + (x + 1))= (2x)(4x + 2)= 2x(2x + 1)`

`26. x^3y^3 + 125= (xy)^3 + 5^3= (xy + 5)((xy)^2 - 5xy + 25)= (xy + 5)(x^2y^2 - 5xy + 25)`

`27. 8x^3 - y^3 - 6xy(2x - y)= 8x^3 - y^3 - 12x^2y + 6xy^2= (2x - y)^3`

`28. (3x + 2)^2 - 2(x - 1)(3x + 2) + (x - 1)^2= ((3x + 2) - (x - 1))^2= (2x + 3)^2`

`@612009`