If the shifted items are addition and subtraction, it is the same as multiplication and division.

The shifted item is multiplication and division. At this time, we should pay attention to two points.

(1) If the shift term is negative, the sign of the equal sign should be changed.

(2) If the shift term may be 0, when the shift term is used as the denominator, the case that it is 0 should be considered first to prevent negligence.