input: 
  def linear_eq(a: float, b: float, c: float, x: float, y: float) -> float:
      """Calculate the result of the objective function of a linear equation ax + by - c.
      >>> linear_eq(3, 5, 7, 1, 1)
      1.0
      >>> linear_eq(1, 2, 3, 2, 2)
      3.0
      """
      return a*x + b*y - c
  
output:     return a*x + b*y - c