PSAT Math Multiple-Choice Question 734: Answer and Explanation

Question: 734

What is the difference between 7a² + 3ab - 8b and -2a² + ab - 2b?

• A. 5a² + 4ab - 10b
• B. 9a² + 4ab - 8b
• C. 9a² + 2ab - 6b
• D. 7a + 3ab - 10

Correct Answer: C

Explanation:

(C) The "difference" between two terms is the result when you subtract one term from another. Subtract one term from another. This is easiest to do if you place one term over the other so you can easily match up common terms and carefully apply the negative sign: