# SAT Math Multiple Choice Question 314: Answer and Explanation

Home > SAT Test > SAT Math Multiple Choice Practice Tests

### Test Information

- Use your browser's back button to return to your test results.
- Do more SAT Math Multiple Choice Practice Tests.

**Question: 314**

**14.** If a + bi represents the complex number that results from multiplying 3 + 2i times 5 - i, what is the value of a?

- A. 2
- B. 13
- C. 15
- D. 17

**Correct Answer:** D

**Explanation:**

D

Difficulty: Medium

Category: Additional Topics in Math / Imaginary Numbers

Strategic Advice: Multiply the two complex numbers just as you would two binomials (using FOIL). Then, combine like terms and use the definition i2 = -1 to simplify the result.

Getting to the Answer:

The question asks for a in a + bi, so the correct answer is 17.