using the commutative law the equivalent expression for k+ts would be ts +k am I right?

Yes, you are correct! According to the commutative law of addition, the order of the numbers being added does not affect the result. This means that you can rearrange the terms in the expression k + ts without changing its value.

So, ts + k is indeed equivalent to k + ts. Both expressions represent the addition of the variables k and ts, but in a different order.