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.
  
      >>> solve_linear_equation_system(2, 1, 4)
      (2.0, 2.0)
      """
      x = (c - b) / a
      y = (c - a*x) / b
      return x, y
output:     x = (c - b) / a
      y = (c - a*x) / b
      return x, y