If k^2 = n^2, which of the following must be true?	Select
A) k = m B) k = -m C) |k| = |n| D) k = -|m| E) k = |m|
Solution:   We are given that k^2 = n^2, and we can start by simplifying the equation by taking the square root of both sides.   √k^2 = √n^2   When we take the square root of a variable squared, the result is the absolute value of that variable. Thus:   √k^2 = √n^2 is |k| = |n|   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| = |n|
<result>C</result>
If k^2 = n^2, which of the following must be true?