GMAT Problem Solving (PS) | Re: If |m+5|−5 = m, which of the following must be true?

Make a positive and a negative case

|m + 5| - 5 = m --> |m + 5| = m + 5

Positive:
m + 5 = m + 5 --> m = 0

Negative
m + 5 = -m - 5
2m = -10 --> m = -5

As you can see only answer D satisfy both conditions.

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