The binomial [tex]x^2 - 64[/tex] is special type of binomial called the difference of squares. A difference of squares is a binomial in which both of the terms are perfect squares.
[tex]x^2 - y^2 = (x + y)(x - y)[/tex]
[tex]x^2 - 64 = (x + 4)(x - 4)[/tex]
So, (x + 4)(x - 4) is the answer.
