The blame should be put squarely on the shoulders of tophatter.com. They know the quality of what is being sold and choose to look the other way for the sake of making commission and sales fees on these imitation goods. In my estimation and also the interpretation of the law this is outright FRAUD.
Inverse operations are opposite operations that undo each other. Addition and subtraction are inverse operations. Multiplication and division are inverse operations.
Addition Property of Equality Examples. In solving equations, it is required to work backward. This is to 'undo' the operation that has been done using the reverse operations. So addition is done to undo subtraction and vice-versa.