二1.若2x+3y=2008,则代数式2（3x-2y)-(x-y)+9-x+9y)= 三.x^2+3x+k是完全平方式,

一分解因式
1.m^2(a-m)(a-n)+n^2(m-a)(a-n)
=（a-m)(a-n)[m^2-n^2]
=(a-m)(a-n)(m+n)(m-n)
2.9(2a+b)^2-25(a-b)^2
=[3(2a+b)+5(a-b)][3(2a+b)-5(a-b)]
=[11a-2b][a+8b]
3.-3x^n+1+6x^ny-3x^n-1y^2
=-6x^n(1-y )+1-y^2
=(1-y)(1+y-6x^n)
4.(3x-1)^3-(12x-4)
=(3x-1)^3-4(3x-1)
=(3x-1)[(3x-1)^2-4]
=3(3x-1)(3x-5)(x+1)
5.(x^3-4x^2y+4xy^2)-x+2y
=x(x^2-4xy+4y^2)-(x-2y)
=(x-2y)[x(x-2y)-1]
=(x-2y)(x^2-2xy-1)
6.4m^2-n^2-4m+1
=(2m-1)^2-n^2
=(2m-1+n)(2m-1-n)
二.
( a^4 )/a=a^3
四.x^2+3x+k是完全平方式,则k=2.25

一分解因式 1.m^2(a-m)(a-n)+n^2(m-a)(a-n) 2.9(2a+b)^2-25(a-b)^2 3.-3x^n+1+6x^ny-3x^n-1y^2 4.(3x-1)^3-(12x-4) ...

如此基础的题目自己懒的做就来知道？要答案去抄作业不就行了呗