input: from typing import Tuple
  
  def solve_linear_equation_system(a: float, b: float, c: float) -> Tuple[float, float]:
      """ Solve a linear equation system of the form ax + by = c given coefficients a, b, and c.
      >>> x, y = solve_linear_equation_system(2, 1, 4)
      >>> print("x = {}, y = {}".format(x, y)) # x = 2.0, y = 2.0
      """
output:     if a == 0 and b == 0:
          raise ValueError("Both coefficients a and b cannot be zero.")
      elif a == 0:
          return (0, c / b)
      elif b == 0:
          return (c / a, 0)
      else:
          return (c / a, 0)