COMMON BASE

When multiplying and dividing expressions involving exponents, you must have a common base. The following are examples of exponents that share a common base:

The following examples of exponents do not share a common base:

In the last example, n and o are not common or the same and x and xy are not common or the same. When you have a common base, you may perform the mathematical operations, but when you do not have a common base, you may not perform the mathematical operations.