Factoring polyminals functions algebra 1

Factor 9x^2 - 64 completely. help?

difference of two squares:

9x^2 - 64 = (3x-8)(3x+8)

(9x^2 + 24x - 24x -64, and then the 24x's cancel eachother out)

Since 9, x^2, and 64 are all perfect squares, we can take the square root to factor the function.
The factored form is:

(3x-8)(3x+8)

(3x+8)(3x-8)

(3x+8)(3x-8)