数学问题……请帮忙！（简单的分解因式）

1.1/16-m^4
=（1/4)^2-(m^2)^2
=（1/4+m^2)(1/4-m^2)
=（1/4+m^2)[（1/2)^2-m^2]
=（1/4+m^2)(1/2+m)(1/2-m)

2.a^5-a^2b^3
=a^2(a^3-b^3)
=a^2(a-b)(a^2+ab+b^2)

3.(a+1)^2-(a+b)^2
=(a+1+a+b)(a+1-a-b)
=(2a+b+1)(1-b)

4.-1/2a^5+8a^3
=-1/2a^3(a^2-8)

5.1/125x^3 y^ 6 z^9-3又3/8
=(1/5xy^2 z^3)^3-(3/2)^3
=(1/5xy^2 z^3-3/2)[(1/5xy^2 z^3)^2+3/2×1/5xy^2 z^3+3/2^2)]
=(1/5xy^2 z^3-3/2)(1/25x^2y^4z^6+3/2×1/5xy^2 z^3+9/4)]

6.3x^m-1+81x^m+2
=3x^m-1(1^3+27x^3)
=3x^m-1(1+27x)[(1/3)^2-1/3×27x+(27x)^2]
=3x^m-1(1+27x)(1/9-9x+729x^2)

嘛..大概就这样..这部分莪也不怎么擅长...后面几题没什么把握..