"...charges a flat rate of $5.00..." Flat rates in the business world is what we call constants in the mathematical word. That is, if we have a flat rate, that number doesn't change for anything because it has no variable attached to it (unless otherwise noted). You can identify what the constants are because they do not have the tags "per", "each", or "for every" attached to them when in the English language. In this case, this number remains the same no matter if 1 package gets shipped or a 1000 packages get shipped. So, we have the first part of our equation:
