數學 factorization!! 15分7題(急)

8x3-1 = (2x) 3 – (1) 3=(2x-1)(4x2+1+2x)
27+z3=33+z3=(3+z)(9+z2-3z)
x2-14x-72=(x-18)(x+4)
4x2-4x-15
=(2x-5)(2x+3)
3x2-7x-6
=(x-3)(3x+2)
2x2-22x+48
=2(x2-11x+24)=2(x-8)(x-3)
54y3+2x3z6=2(27 y3+x3z6)=2[(3y)3 + (xz2)3]=2[(3y+xz2)(9y2+x2z4-3xyz2)]

8x3-1
=(2x)^(3)-1^(3)
=(2x-1)(4x^(2)+2x+1)

27+z3
=3^(3)+z^(3)
=3^(3)-z^(3)
=(3-z)(9+3z+z^(2))

x2-14x-72
=(x-18)(x+4)

4x2-4x-15
=(2x-5)(2x+3)

3x2-7x-6
=(3x+2)(x-3)

2x2-22x+48
=(2x-16)(x-3)

54y3+2x3z6
=2(27y^(3)-x^(3)z^(6))
=2((3y)^(3)-(xz^(2))^(3))
=2[(3y-xz^(2))((3y)^(2)+(3y)(xz^(2))+(xz^(2))^(2))
=2[(3y-xz^(2))(9y^(2)+3xyz^(2)+x^(2)z^(4))]


2011-08-31 15:05:12 補充：
Correct=

27+z3
=3^(3)+z^(3)
=3^(3)+z^(3)
=(3+z)(9+3z+z^(2))

54y3+2x3z6
=2(27y^(3)+x^(3)z^(6))
=2((3y)^(3)+(xz^(2))^(3))
=2[(3y+xz^(2))((3y)^(2)+(3y)(xz^(2))+(xz^(2))^(2))
=2[(3y+xz^(2))(9y^(2)+3xyz^(2)+x^(2)z^(4))]