SAT Math Multiple Choice Practice Question 62: Answer and Explanation
18. If vw = x, wx = y, and xy = z, which of the following would be equal to yz?
Correct Answer: B
B. The answer choices have only v and w in them, so you need to start this problem by turning everything into those letters. You already know that x = vw, so y = wx = w(vw) = vw2. To continue, you need to remember two things: First, the ws both have an "invisible 1" as their exponents, and second, you need to add exponents when you multiply powers of the same bases. Because z = xy, z = (vw)(vw2) = v2w3. You're looking for yz, which your work tells you equals (vw2)(v2w3) = v3w5.