4、2x3y)(4x26xy9y2)；16、(a22)(a42a24)17、(3x22x1)(2x23x1)18、(y1)(y2)(y3)19、（a4）(a+3)（2a+1）（a3）20、（x+2）（x3)x（x2）21（x3）（x2一6x+1）x（x2一x3）22(a2b)2(ab)(ab)2(a3b)(ab)，(1)(2x3y)(3x2y)(2)(3x1)(4x5)(3)(x3)(x4)(x1)(x2)(4)(3x2y)(2x3y)(x3y)(3x4y)(5)(x2)(x3)(x6)(x1)(1)(m1)(2m1)；(2)(2a3b)(3a2b)；(3)(2x3
5、y)(4x26xy9y2)；(1)(ab)(ab22abb1)；(2)3ab(a2bab2ab)ab2(2a23ab2a)(4)(2xy)(xy)；(5)a(a3)(2a)(2a)三、因式分解8、(1)(2)(3)(4)(5)3x36x4；(6)4a3b210ab3c；(7)3ma36ma212ma；(8)6p(pq)4q(pq)(9)x4x3x；(10)x(xy)y(yx)；(11)6x(ab)4y(ba)；(12)(a2ab)c(ab)；(13)4q(1p)32(p1)2.(1)(2)(3)(4)(5)4x2y2；(6)16a2b2；(7)100x29y
6、2；(8)(x2y)2(xy)2；(9)16b4.(10)a39a；(11)3m(2xy)23mn2；(12)(ab)b24(ab)(1)(2)(3)(4)（5）3p26pq；（6）2x2+8x+8（7）2am28a；（8）4x3+4x2y+xy2（1）（2）（3）（4）（5）（6）32.24x312x228x33.6(mn)312(nm)234.3(ab)26(ba)35.18(ab)312b(ba)236.(2ab)(2a3b)3a(2ab)37.(x26x)2(2x4)238.9(mn)2(mn)239.(2x3y)2140.9(ab)
7、216(ab)241.(xy)216(xy)242.16x481y443.3ax23ay244.2x38x45.7x26346.(a2b2)24a2b247.(mn)26(mn)948.(3)(ab)22(ab)1;49.4xy24x2yy350.x24y24xy51.；52.；53.(a24)216a254.-4x3+16x2-26x56.a2(x-2a)2-a(2a-x)357.56x3yz+14x2y2z21xy2z258.mn(mn)m(nm)59.-(2a-b)2+4(a-b)260.4xy(x2-4y2)61.-3ma3+6ma2-12ma62.a2(x-y)+b2(y-x)63.64.65.2x