Question

Anyone knows how to solve these kind of questions (factorize)?

1) a^2b^2-a^2c^2
2)(a^2-b^2)x^2+b^2-a^2
3) a-a^2/16
4) 1/4-x+x^2
5) 2x^3-6x^2y-56xy^2
6)9a^2b+30ab^2+9b^3
7) ax^2+(a+1)x+1
8) abx^2-(a^2+b^2)x+ab