input: def solve_linear_equation_system(a: float, b: float, c: float) -> tuple:
      """
      Solve a linear equation system of the form: ax + by = c.
      
      >>> solve_linear_equation_system(2, 1, 4)
      (2.0, 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)