input: def solve_linear_equation_system(a: float, b: float, c: float) -> tuple:
      """ Solve a linear equation system of the form: ax + by = c.
      >>> x, y = solve_linear_equation_system(2, 1, 4)
      >>> print(f"x = {x}, y = {y}")
      x = 2.0, y = 2.0
      """
output:     if a == 0 and b == 0:
          if c == 0:
              return (float('inf'), float('inf'))
          else:
              return None
      elif a == 0:
          return (float('inf'), c / b)
      elif b == 0:
          return (c / a, float('inf'))
      else:
          return (c / a, float('inf'))