Phân tích thành nhân tử giúp vs ạ

`7)(x+y)^2 - 8(x+y) + 12 `

`= x^2 + 2xy + y^2 - 8x - 8y + 12 `

`= x^2 + 2xy + y^2 - 2x - 2y - 6x - 6y + 12 `

`= (x^2 + 2xy + y^2 - 2x - 2y) - (6x + 6y - 12)`

`= [x(x+2y) + y^2 - 2(x+y)] - 6(x+y-2) `

`= (x+y)(x+y-2) - 6(x+y-2)`

`= (x+y-2)(x+y-6) `

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

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

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

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

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

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

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

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

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

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

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

`9) (x^2+x)^2 + 4x^2 + 4x - 12 `

`= x^4 + 2x^3 + x^2 + 4x^2 + 4x - 12 `

`= x^4 + 2x^3 + 5x^2 + 4x - 12 `

`= x^4 + 2x^3 - x^2 + 6x^2 + 4x - 12`

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

`= x^2(x^2 + 2x - 1) + 2(3x^2 + 2x - 6) `

`= (x^2 + x - 2)(x^2 + x + 6) `

`=(x^2-x+2x-2)(x^2+x+6)`

`=[x(x-1)+2(x-1)](x^2+x+6)`

`= (x-1)(x+2)(x^2 + x + 6)`

`10) (x^2+2x)^2 + 9x^2 + 18x + 20 `

`=x^4+2x^3+5x^2+2x^3+4x^2+10x+4x^2+8x+20`

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

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

`11) (x^2+x)^2 - 2(x^2+x) - 15 `

`= x^4 + 2x^3 + x^2 - 2x^2 - 2x - 15 `

`= x^4 + 2x^3 - x^2 - 2x - 15 `

`=x^4+x^3-5x^2+x^3+x^2-5x+3x^2+3x-15`

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

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

`12) (x^2+4x)^2 - 2(x^2+4x) - 15`

`= x^4 + 8x^3 + 16x^2 - 2x^2 - 8x - 15`

`= x^4 + 8x^3 + 14x^2 - 8x - 15 `

`=x^4+4x^3-5x^2+4x^3+16x^2-20x+3x^2+12x-15`

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

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

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

`=[x(x+3)+(x+3)][x(x-1)+5(x-1)]`

`= (x+1)(x+3)(x+5)(x-1)`

`@` ltmn