因式分解专项练习

因式分解专项练习1. ax 2−2ax+a 2. 3. 4 xy2−4 xy+x 4. 5. 6. x2 y−2 xy+ y7.3 x−12 x3 8. 9. x3−2x2+x 10. 4 x3−8x2+4 x11. −4m3+16m2−16m 12. −x3+x713．2ax2−8axy+8ay 2 14. 16 x4−256 y 415. −a+2a2−a3 16. 3ax 2+6 axy+3ay217. x3 z−4 x2 yz+4 xy 2 z 18. −x2−4 y2+4 xy