input: def linear_eq(a: float, b: float, c: float, x: float, y: float) -> float:
      """ Given the coefficients of a linear equation, calculate the objective function.
      
      >>> linear_eq(3, 5, 7, 2, 1)
      -1.0
      >>> linear_eq(3, 5, 7, 3, 0)
      2.0
      """
      return a*x + b*y - c
output:     return a*x + b*y - c