Question

1)x^3 -2x-1

2) x^3 +3x^2 -4

3) x^3y^3 +x^2y^2 +4

4) x^3 + 5x^2 -9xy^2, +5y^3

5) x^4 + x^3 + 6x^2 + 5x + 5

Answer 1

Yêu cầu là gì v c.

Answer 2

`@` `\text {Ans}`

`\downarrow`

`1)`

`x^3 - 2x - 1`

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

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

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

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

`2)`

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

`= x^3 + 4x^2 + 4x - x^2 - 4x - 4`

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

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

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

`3)`

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

`= x^3 y^3 - x^2y^2 + 2x^2y^2 + 2xy - 2xy + 4`

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

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

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

Answer 3

`4)`

`x^3 + 5x^2 -9xy^2+5y^3`

Bạn xem lại đề ;-;

`5)`

` x^4 + x^3 + 6x^2 + 5x + 5`

`= x^4 + x^3 + 5x^2 + x^2 + 5x + 5`

`= (x^4 + x^3 + x^2) + (5x^2 + 5x + 5)`

`= x^2(x^2 + x + 1) + 5(x^2 + x + 1)`

`= (x^2 + 5)(x^2 + x + 1)`