input: def solve_linear_equation_system(a: float, b: float, c: float) -> tuple:
      """ Solve a linear equation system of the form ax + by = c.
      Return the solution as a tuple (x, y).
      >>> solve_linear_equation_system(2, 1, 4)
      (2.0, 2.0)
      """
output:     if a == 0 and b == 0:
          raise ValueError("The coefficients a and b cannot both be zero.")
      if a == 0:
          return (0, c / b)
      if b == 0:
          return (c / a, 0)
      return (c / a, 0)