A guy from HUST

This page lists questions and answers that were posted by visitors named A guy from HUST.

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The following questions were asked by visitors named A guy from HUST.

Answers

The following answers were posted by visitors named A guy from HUST.

July 3rd 2021, almost 11 years later, I had the same problem with this. Thank you so much for showing the exact purpose of both formulas