As long as they have the same radix, the same radix power can be added or subtracted. When two powers have the same radix, the following rules can be used for addition and subtraction:

1. Power addition rule:

If two powers have the same radix (called a), they can be added. In this case, the exponents (called n and m) will remain the same, while the cardinality will remain the same. The result is a new power, its base is still a, and the exponent is the sum of the exponents of the original two powers. Namely:

Answer? + a？ = a^(n + m)

2. Power subtraction rules:

Similarly, if two powers have the same radix (called a), they can be subtracted. In this case, the exponents (called n and m) will remain the same, while the cardinality will remain the same. The result is a new power, its base is still a, and the exponent is the difference between the exponents of the original two powers. Namely:

Answer? - a？ = a^(n - m)

These rules are valid for any real number a and integers n and m, as long as the cardinality is the same. When the cardinality is different, the power cannot be added or subtracted directly.