Why do we need to subtract the 32.50 rather than adding the 32.50

The need for subtracting or adding 32.50 will depend on the context of the problem. In some cases, subtracting 32.50 may be necessary while in others adding 32.50 may be appropriate. Without specific information about the problem or equation you are referring to, it is difficult to provide a definitive answer. Could you please provide more details or context?