Phân tích đa thức thành nhân tử

1) 4x2  – 25 + (2x + 7)(5 – 2x)                                      9) x3  + x2y – 4x – 4y

2) 3(x+ 4) – x2 – 4x                                                     10)  x3  – 3x2 + 1 – 3x

3) 5x2 – 5y2 – 10x + 10y                                            11) 3x2 – 6xy + 3y2 – 12z2

4) x2  – xy + x – y                                                         12) x2  – 2x – 15

5) ax – bx – a2  + 2ab – b2                                           13) 2x2  + 3x – 5

6) x2  + 4x – y2 + 4                                                       14) 2x2 – 18

7) x3 – x2 – x + 1                                                          15) x2 – 7xy + 10y2

8) x4  + 6x2y + 9y2 - 1                                                   16) x3 – 2x2 + x – xy2

giải giùm mik nhak!
camon!!!