文档介绍：一、计算
·(-a)5·(-3a)3
2.[(am)n]p
3.(-mn)2(-m2n)3
4.(-a2b)3·(-ab2)
5.(-3ab)·(-a2c)·6ab2
6.(-ab)3·(-a2b)·(-a2b4c)2
7.(3m-n)(m-2n).
8.(x+2y)(5a+3b).
(x2+2x+1)-(2x+3)(x-5)
10. (-2x-5)(2x-5)
11. -(2x2+3y)(3y-2x2)
12. (a-5) 2-(a+6)(a-6)
13. (2x-3y)(3y+2x)-(4y-3x)(3x+4y)
14. 3(2x+1)(2x-1)-2(3x+2)(2-3x)
15. (x+y)(x-y)(x2+y2)
16.
二、基础训练
-12xy3z的公因式是_________.
-6ab2+18a2b2-12a3b2c的公因式是( )
A.-6ab2c B.-ab2 C.-6ab2 D.-6a3b2c
( )
-9a2b2=3abc(4-3ab) -3xy+6y=3y(x2-x+2y)
C.-a2+ab-ac=-a(a-b+c) +5xy-y=y(x2+5x)
( )
-20a2b2 -15ab4-10a3b2
-20a2b3+50a4b -10a3b3+15a4b2
( )
A.-2ab2+4a2b=2ab(-b+2a) (a-b)-9n(b-a)=3(a-b)(m+3n)
C.-5ab+15a2bx+25ab3y=-5ab(-3ax-5b2y); -6ay-3a=3a(y2-2y-1)
:
(1)ma+mb+mc=m(________); (2)多项式32p2q3-8pq4m的公因式是_________;
(3)3a2-6ab+a=_________(3a-6b+1);(4)因式分解:km+kn=_________;
(5)-15a2+5a=________(3a-1); (6)计算:21×-31×=_________.
:
(1)8ab2-16a3b3; (2)-15xy-5x2;
(3)a3b3+a2b2-ab; (4)-3a3m-6a2m+12am.
:-(a-b)mn-a+b.
三、提高训练