In the first case, two pieces of fabric are 8 m shorter than the first one. How many dresses were sewn, if each dress used 4 meters of fabric?

Solution:

1. Determine the length of the second piece of fabric: 8 m - 8 m = 0 m.
2. The problem states that the second piece of fabric is 8 meters shorter than the first. However, the given value for the first piece of fabric is not provided. Let's assume the first piece of fabric has a length of X meters. Then the second piece has a length of X - 8 meters.
3. The problem states: "From the second piece of fabric, they sewed dresses, using 4 meters of fabric for each dress." However, without knowing the length of the second piece of fabric, we cannot determine how many dresses were sewn.
4. There seems to be missing information in the problem statement to provide a definitive numerical answer.

Answer: The problem statement is incomplete, as the length of the first piece of fabric is not provided.