To factor the expression 16x^2 - 49, you can use the difference of squares formula, which states that a^2 - b^2 = (a + b)(a - b). In this case, a = 4x and b = 7. So, the factored form is:
16x^2 - 49 = (4x + 7)(4x - 7)
Therefore, the factored expression is (4x + 7)(4x - 7).