文档介绍：一、·(-a)5·(-3a)32.[(am)n]p3.(-mn)2(-m2n)34.(-a2b)3·(-ab2)5.(-3ab)·(-a2c)·6ab26.(-ab)3·(-a2b)·(-a2b4c)27.(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)(2x+1)(2x-1)-2(3x+2)(2-3x)15.(31x+y)(31x-y)(91x2+y2)16.)1)(1)(1)(1(42xxxx????二、基础训练1. 多项式8x3y2--6ab2+18a2b2-12a3b2c的公因式是()A.-6ab2cB.-ab2C.-6ab2D.-()-9a2b2=3abc(4-3ab)-3xy+6y=3y(x2-x+2y)C.-a2+ab-ac=-a(a-b+c)+5xy-y=y(x2+5x)()--15ab4--20a2b3+-10a3b3+()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+:-(a-