input: Write a Python function to check if a given number exists within an infinite sequence.
  
  assert does_Contain_B(1,7,3) == True  
  assert does_Contain_B(1,-3,5) == False  
  assert does_Contain_B(3,2,5) == False
output: def does_Contain_B(start, diff, number):
      if diff == 0:
          return number == start
      return (number - start) % diff == 0 and (number - start) // diff >= 0