PSAT Math Multiple-Choice Question 12: Answer and Explanation

Question: 12

Which of the following shows the expression in the form of A·(B)^y?

• A.
• B.
• C.
• D.

Correct Answer: A

Explanation:

A

The question asks for an expression rewritten in another form. When dealing with questions about exponents, remember the MADSPM rules. The MA part of the MADSPM acronym indicates that Multiplying matching bases means to Add the exponents. Therefore, and the fraction is equivalent to . Taking a number to the power is the same as taking the square root of the number. Therefore, . In order to cancel the terms with y exponents, a common base is needed. Rewrite 16^y as (2 ×)^y or 2^y8^y. Reduce the fraction to get . Simplify the denominator to get . Separate the fraction to get . Only (A) includes the correct fractions. The correct answer is (A).