The expression x^2 - 2x - 15 can be factored into the product of two binomials. To find these binomials, we can use the "ac method," where we try to find two numbers that multiply to -15 and add up to -2. These numbers are -5 and 3. We can then write the expression as:
(x - 5)(x + 3)
So, the expression x^2 - 2x - 15 can be factored as (x - 5)(x + 3).