急!!!!!!!中三的因式分解

A)(1-x)²-(1-y)²=[(1-x)+(1-y)][(1-x)-(1-y)] =(2-x-y)(y-x) B)12(x+y)²-3(x-y)²=3[4(x+y)²-(x-y)²]=3[(2x+2y)²-(x-y)²]=3[(2x+2y)+(x-y)][(2x+2y)-(x-y)] =3(3x+y)(x+3y) C)(c+d)²+4(c+d)+4=(c+d)²+2(c+d)(2)+2² =(c+d+2)² D)16(p-5)²+(p-5)+1 [Unfactorizable. http://wims.unice.fr/wims/wims.cgi?session=PQ1FA99A5D.1&lang=en&cmd=reply&module=tool%2Falgebra%2Ffactor.en&calc=factor&formula=16%28p-5%29^2%2B%28p-5%29%2B1]E)16-24(h-5k)+9(h-5k)²=4²-2(4)[3(h-5k)]+[3(h-5k)]²=[4-3(h-5k)]²=(15k-3h+4)²

2011-10-22 15:03:28 補充：
D)16(p-5)²+8(p-5)+1

=[4(p-5)]²+2[4(p-5)](1)+1²

=[4(p-5)+1]²

=(4p-19)²

2011-10-22 16:15:48 補充：
註：(15k-3h+4)²=(3h-15k-4)^2

A
(1-x)^2-(1-y)^2
=[(1-x)+(1-y)][(1-x)-(1-y)]
=(1-x+1-y)(1-x-1+y)
=(-x-y+2)(-x+y)

B
12(x+y)^2-3(x-y)^2
=3[4(x+y)^2-(x-y)^2]
=3[2(x+y)-(x-y)][2(x+y)+(x-y)]
=3(2x+2y-x+y)(2x+2y+x-y)
=3(x+3y)(3x-y)

C
(c+d)^2+4(c+d)+4
=[(c+d)+2]^2
=(c+d+2)^2

D
16(p-5)^2+8(p-5)+1
=[4(p-5)+1]^2
=(4p-20+1)^2
=(4p-19)^2
E
16-24(h-5k)+9(h-5k)^2
=9(h-5k)^2-24(h-5k)+16
=[3(h-5k)-4]^2
=(3h-15k-4)^2