PSAT Math Multiple-Choice Question 764: Answer and Explanation

Question: 764

6a² + 8ab – 4ac is equivalent to which of the following expressions?

• A. a(3a + 4b + 2c)
• B. 2a(3a + 4b – 2c)
• C. 4a(a + b – 2c)
• D. 2a(3a - 4b + 2c)

Correct Answer: B

Explanation:

(B) Factor out all common factors. 2a is a factor of all three terms, so it can be factored out:
2a(3a + 4b - 2c)
Alternatively, you could have redistributed the answer choices to eliminate choices (A), (C), and (D), which, respectively, equal, 3a² + 4ab + 2ac, 4a² + 4ab - 8ac, and 6a² - 8ab + 4ac.