input: Write a python function to subtract 10 from each element in a list.
  assert subtractFromList([20, 30, 40]) == [10, 20, 30]
  assert subtractFromList([50, 60, 70]) == [40, 50, 60]
  assert subtractFromList([10, 20, 30]) == [0, 10, 20]
output: def subtractFromList(lst):
      return [x - 10 for x in lst]