15 feet. When the second piece is 0 feet long, the first is 15 feet long, so that is the length of the ribbon.
-1. For each length the second piece increases by, the first piece must decrease by the same length. For example, if we want the second piece to be 1 foot longer, then the first piece must be 1 foot shorter.
Three possible pairs: \((14.5,0.5)\), which means the second piece is 14.5 feet long so the first piece is only a half foot long. \((7.5,7.5)\), which means each piece is 7.5 feet long, so the original ribbon was cut in half. \((0,15)\), which means the original ribbon was not cut at all to make a second piece, so the first piece is 15 feet long.

8.3 Family Material