PSAT Math Multiple-Choice Question 771: Answer and Explanation

Question: 771

If for all values of x, what is the value of a?

• A. 0
• B. 3
• C. 5
• D. 16

Correct Answer: B

Explanation:

(B) Let's try to simplify the left side of the equation a bit to get it in the same form as the right side. When an exponent is raised to another exponent, you multiply those exponents:

Also, can be broken up into . Since , the expression can be further simplified:

Therefore, the left side of the equation simplifies to:

You can then combine like terms:

If , then it follows from dividing both sides by that a = 3, which is
choice (B).