Difficulty: Easy
Correct Answer: 1/x^2
Explanation:
Introduction / Context:
This problem combines cube roots with integer and negative exponents. Converting all radicals to fractional exponents allows straightforward combination via exponent addition and subtraction rules.
Given Data / Assumptions:
Concept / Approach:
Use ∛(x^k) = x^(k/3). Then combine exponents linearly: when multiplying, add exponents; when dividing, subtract exponents. Keep track of the signs carefully, especially for the negative power term x^(−3).
Step-by-Step Solution:
Verification / Alternative check:
Pick x = 2: ∛(64)/∛(4096) × 2^(−3) × ∛(512) = 4/16 × 1/8 × 8 = (1/4) × (1/8) × 8 = 1/4 = 1/2^2, confirming 1/x^2.
Why Other Options Are Wrong:
Common Pitfalls:
Forgetting that dividing by x^4 reduces exponent by 4, or cancelling x^(−3) incorrectly with x^3.
Final Answer:
Discussion & Comments