Which operation is performed when simplifying (3²)⁴?

When simplifying the expression ((3²)⁴), the operation performed involves multiplying the exponents. This is based on the exponentiation rule that states when raising a power to another power, you multiply the exponents.

In this case, you have (2) as the exponent of (3) and then you raise (3²) to the power of (4). According to the rule, you can write this as (3^{2 \cdot 4}). Performing the multiplication gives you (3^8).

Thus, the process of multiplying the exponents is the correct operation to apply when simplifying this expression. This leads to (3^8) as the final simplified form.