Question

[lenam]

Bài 2: Phân tích các đa thức sau thành nhân tử. (Nhóm xuất hiện hằng đẳng thức).

          1) x³ – x + y³ - y                                  2) x² – 2xy – 4z² + y²                

3) x(x – 1) – y(1 – x)                           4) x³ + 6x²y + 12xy² + 8y³                   

5) x² – 2xy + y² – xz + yz                    6) x² – y² – x + y                                 

7) 3x² + 6xy + 3y² – 3z²                       8) x² – 2xy + y² – z² + 2zt – t²

          9) x³ + x² – xy + y² + y³                       10) x² – 6(x + 3) - 9 

Answer 1

[Nguyễn Huy Tú]

1, \(\left(x+y\right)\left(x^2-xy+y^2\right)-\left(x+y\right)=\left(x+y\right)\left(x^2-xy+y^2-1\right)\)

2, \(\left(x-y\right)^2-4z^2=\left(x-y-2z\right)\left(x-y+2z\right)\)

3, \(x\left(x-1\right)+y\left(x-1\right)=\left(x+y\right)\left(x-1\right)\)

4, \(x^3+6x^2y+12xy^2+8y^3=\left(x+2y\right)^3\)