八年级数学因式分解 (2017.12.7)1、提公因式法因式分解(1)3mx-6my (2)x2y+xy2 (3)12a2b3-8a3b2-16ab4(4)3x2-6xy+x (5)-24x3 –12x2 +28x (6)2a(y-z)-3b(z-y)2、用平差因式分解 (1) 36-x2 (2) a2- b2 (3) x2-16y2(4) x2y2-z2 (5) (x+2)2-9 (6)(x+a)2-(y+b)2(7) 25(a+b)2-4(a-b)2 (8)-0.25(x+y)2+0.81(x-y)23、用完全平公式 因式分解:(1)a2-4a+4 (2)a2-12ab+36b2 (3)25x2+10xy+y2 (4)16a4+8a2+1 (5) (m+n)2-4(m+n)+4 (6) 16a4-8a2+14、用十字相乘法因式分解: 13. 14. 15 . 16. 5、用分组分解法因式分解:(7)、 (8). (9) (10) (11) (12) (13) (14) (15) (16) (17) (18) (19) (20) 6、因式分解:(1)18a2-50 (2)2x2y-8xy+8y (3)a2 (x-y)-b2(x-y) (4) (5)a4-16 (6)81x4-72x2 y2+16y4 (7)(a2+b2)2-4a2b2 (8) (9)a4-2a2b2+b4 (10)-2xy-x2-y2 (11)3ax2+6axy+3ay2 ( 12) (13)(x2-2y)2-(1-2y)2(14)x4-2x2+1 (15)x4-8x2y2+16y4 (16)80a2(a+b)-45b2(a+b) (17)16a4+24a2b2+9b4 (18)(x+y)2-10(x+y)+25(20)4m 2-9n2-4m+1 (21)3a2+bc-3ac-ab (22)(x+y)(x+y-1)-12(23) (24) (25) (26) (27) (28) (29) (30) (31) (32) 7、利用因式分解计算:(1) (2)20042- |