1.(x-5)(x² + 10x + 25)                                    

 2. (x + 10)(x-3)                                            

 3. 2(x² + 5)(x⁴ - 5x² + 25)                             

 4. 2(x-2)(x+2)²(x² - 2x + 4)          

5. 4(2x + 5)(2x - 5)                                       

6. (3x - 2)(x + 4)                        

7. 5(x² - 7x - 36)                                            

8. (5x - 2)(5x + 2)                                         

9. (x - 6)(x + 5y)                                              

10. 2(x + 2)(3x - 7)                      

11. 2(x + 2)(x² - 2x + 4)(x-2)(x² + 2x +4)      

12. (x² + y²)(x⁴ -x² y² + y⁴)