PSAT Math Multiple-Choice Practice Question 712

Correct Answer: C

Explanation:

(C) Use FOIL for this like you would anything else. When you FOIL the expression, you get:

12 + 3i - 4i - i² = 12 - i - i²

Because , i² = -1. Thus, we can rewrite our equation as:

12 - i -(-1)

Therefore, the final answer is 13 - i, which is choice (C).