Subtraction is closed for polynomials subtracting two polynomials will result in another polynomial. Same goes with multiplication. However, if you divide polynomials, you are able to get a result that is not always a polynomial. Therefore, division is the answer.
650 kgs is equal to 1,433 lbs. I believe the mistake would be that they forgot to add a period in between 65 and the 0, because 65.0 kgs is equal to 143.3 lbs.
