1.3x^6-3x^2
=3x^2（x^4-1)
=3x^2(x^2+1)(x^2-1)
=3x^2(x^2+1)(x+1)(x-1)
2.(a^2-2b)^2-(1-2b)^2
=(a^2-2b+1-2b)( a^2-2b-1+2b)
=(a^2+1)(a^2-1）
=（a^2+1)(a+1)(a-1)
3.9x^4-36y^2
=9(x^4-4y^2)
=9(x^2+2y)(x^-2y)
4.4(x+y)^2-(x-y)^2
=^2-(x-y)^2
(2x+2y+x-y)(2x+2y-x+y)
=(3x+y)(x+3y)
5.x^2-3
=(x+根号3)(x-根号3)
6.x^2-5y^2
=(x+根号5>