input: Write a python function to apply transformations on a list: multiply odd numbers by 2 and then subtract 3 from each element.
  assert transformations([1, 2, 3, 4, 5]) == [-1, 3, 7]
  assert transformations([7, 8, 10, 15]) == [11, 27]
  assert transformations([9, 11, 13]) == [15, 19, 23]
output: def transformations(lst):
      return [(x * 2 - 3) for x in lst if x % 2 != 0]