中三數學問題 (多項式)

1. m^2(1-n)^2 - m^2n^2
= (m^2)((1-n)^2 - n^2)
= (m^2)(1-n+n)(1-n-n)
= (m^2)(1-2n)

2a. 4x^2-17xy-15y^2
= (4x+3y)(x-5y)

2b. 將a部得出的答案代入並計算: 4x^2-17xy-15y^2+24x+18y
= 4x^2-17xy-15y^2+24x+18y
= (4x+3y)(x-5y) +24x +18y
= (4x+3y)(x-5y) +6(4x +3y)
= (4x+3y)(x-5y+6)

3. 8x^3+512y^6
= 8(x^3 + 64y^6)
= 8(x^3 + (2^6)(y^6) )
我只懂得做到這裡(sorry~)

2009-10-18 17:57:39 補充：
這條很難我看了書才明白(= =")

第三條的補充:
3. 8x^3+512y^6
= 8(x^3 + 64y^6)
= 8(x^3 + (2y)^6 )
= 8(x+2y)(x^2 -(x)(2y) +(2y)^2)
= 8(x+2y)(x^2 -2xy + 4y^2)

2009-10-21 14:41:37 補充：
這才正確(I think so~)
第三條的補充:
3. 8x^3+512y^6
= 8(x^3 + 64y^6)
= 8(x^3 + (2y)^6 )
= 8(x^3 + ((2y)^2)^3
= 8(x+(2y)^2)(x^2 -(x)(2y)^2 +((2y)^2)^2)
= 8(x+4y^2)(x^2 -4xy^2 + 16y^4)

第3題好似答錯左~~~~~~~~~~