Factor 49t^2 - 9.
A. (7t + 3)(7t + 3)
B. (7t + 3)(-7t - 3)
C. (7t + 3)(7t - 3)
D. 7t - 3
The given expression is a difference of squares. The factors of 49t^2 are 7t and 7t, and the factors of 9 are 3 and 3.
Therefore, the factored form of 49t^2 - 9 is (7t + 3)(7t - 3).
So, the correct option is C. (7t + 3)(7t - 3).