If k^3 = m^3, which of the following must be true?	Choose the correct choice from the following answers.
A) k = m  B) k = -m  C) k = |m|  D) k = -|m|  E) |k| = |m|
Solution:   We are given that k^3 = m^3, and we can start by simplifying the equation by taking the square root of both sides.   3√k^3 = 3√m^3   When we take the square root of a variable squared, the result is the absolute value of that variable. Thus:   3√k^3 = 3√m^3 is |k| = |m|   Note that answer choices A through D could all be true, but each of them would be true only under specific circumstances. Answer choice E is the only one that is universally true.   Answer: |k| = |m|
<result>E</result>
If k^3 = m^3, which of the following must be true?