input: Write a python function to display negative elements from a list.
  assert show_negatives([-1,4,5,-6]) == -1,-6
  assert show_negatives([-1,-2,3,4]) == -1,-2
  assert show_negatives([-7,-6,8,9]) == -7,-6
output: def show_negatives(lst):
      return tuple(x for x in lst if x < 0)