Question: Which of the following is the correct factorization of x^2 + 10x + 21?

Options:

1. (x + 3)(x + 7)
2. (x + 1)(x + 21)
3. (x + 2)(x + 10)
4. (x + 5)(x + 5)

Correct Answer: (x + 3)(x + 7)

Solution:

To factor x^2 + 10x + 21, we look for two numbers that multiply to 21 and add to 10, which are 3 and 7. Thus, it factors to (x + 3)(x + 7).