Simplify the expressions $(-3)^4$ and $-3^4$ to understand the impact of parentheses on the base and the final sign when raising a negative number to an even power:

ⓐ $(-3)^4 = 81$: The base is $-3$. The exponent instructs to multiply $-3$ by itself four times: $(-3)(-3)(-3)(-3) = 81$. Multiplying an even number of negative factors yields a positive product.

ⓑ $-3^4 = -81$: The base is $3$. The expression indicates the opposite of $3^4$. First, calculate the power: $3^4 = 3 \cdot 3 \cdot 3 \cdot 3 = 81$. Next, apply the negative sign to obtain $-81$.

These examples highlight that parentheses include the negative sign in the repeatedly multiplied base, producing a positive result for an even exponent. Without parentheses, the exponent is applied only to the positive integer, and the result is negated afterward according to the order of operations.