Chia đa thức (4x^4-14x^3y-24x^2y^2-54y^4):(x^2-3xy-9y^2)

`\qquad (4x^4-14x^3y-24x^2y^2-54y^4):(x^2-3xy-9y^2)`

`=[(4x^4-12x^3y-36x^2y^2)-(2x^3y-6x^2y^2-18xy^3)+(6x^2y^2-18xy^3-54y^4)]:(x^2-3xy-9y^2)`

`=[4x^2(x^2-3xy-9y^2)-2xy(x^2-3xy-9y^2)+6y^2(x^2-3xy-9y^2)]:(x^2-3xy-9y^2)`

`=(x^2-3xy-9y^2)(4x^2-2xy+6y^2):(x^2-3xy-9y^2)`

`=4x^2-2xy+6y^2`