Answer:
(x - 8)(x + 8) will be your answer.
Explanation:
Lets do this step by step.
1) Find the GCF of the expression.
2x^2 - 32x - 128 --> 2(x^2 - 16x - 64)
2) Use the X-method to factor.
It gives us the expression 2(x^2 - 8x)(-8x -64).
3) Factor for x.
(x^2 - 8x) --> x(x - 8)
(-8x - 64) --> -8(x + 8)
Our answer is (x - 8)(x + 8)