几道数学题 分解因式

1:=abc2-abd2-a2cd+b2cd
=bc(ac+bd)-ad(bd+ac0
=(bc-ab)(ac+bd)
2:=(x-y)(x^2+xy+y^2)+(x+y)(x-y)
=(x-y)(x^2+xy+y^2+x+y)

3:=b^2-(a-1)^2
=(b+a-1)(b-a+1)
4:=(2x+y)(4x-3y)

ab(c^2-d^2)-cd（a^2-b^2)
=abcc-abdd-aacd+bbcd
=ac(bc-ad)+bd(bc-ad)
=(bc-ad)(ac+bd)

x*x*x+x*x-y*y*y-y*y
=(x-y)(x+y+x*x+y*y+xy)

b*b-a*a+2a-1
=b*b-(a-1)(a-1)
=(b+a-1)(b-a+1)

8x*x-2xy-3y*y
=(4x-3y)(2x+y)