help with algebra 2 pre ap?

[Mairah A]

how do i factor polynomials? help


1. 6x2 - 13x + 5

2. 11x^2 - 78x + 7

3. x^2 + 4xy + 4y^2

4. 4a^2 + 12ab + 9b^2

5. 4c^2 - 9

6. 25x^2 - 4y^2

7. 9a^2 - 49b^2