Question 277 of 480
Simplify the expression \( (2^3 \times 2^{-1})^2 \) and express your answer in standard form. What is the result?
- \( 4 \)
- \( 8 \)
- \( 16 \)
- \( 32 \)
Correct Answer:
C
Explanation
To simplify the expression \( (2^3 \times 2^{-1})^2 \) and express the answer in standard form, let's break it down step by step.
### Step 1: Simplify the Inside of the Parentheses
The expression inside the parentheses is \( 2^3 \times 2^{-1} \). When multiplying numbers with the same base, we can use the property of exponents that states:
\[
a^m \times a^n = a^{m+n}
\]
In our case, we have:
\[
2^3 \times 2^{-1} = 2^{3 + (-1)} = 2^{3 - 1} = 2^2
\]
### Step 2: Raise the Result to the Power of 2
Now we need to raise \( 2^2 \) to the power of 2. Again, we can use the property of exponents:
\[
(a^m)^n = a^{m \times n}
\]
Applying this to our expression:
\[
(2^2)^2 = 2^{2 \times 2} = 2^4
\]
### Step 3: Calculate \( 2^4 \)
Now we need to calculate \( 2^4 \):
\[
2^4 = 2 \times 2 \times 2 \times 2 = 16
\]
### Final Answer
Thus, the simplified expression \( (2^3 \times 2^{-1})^2 \) evaluates to \( 16 \).
### Conclusion
The correct option is **C. \( 16 \)**.
### Explanation of Other Options
- **A. \( 4 \)**: This option is incorrect because \( 2^2 = 4 \) is the result of the first part of the expression, but we need to square it to get the final answer.
- **B. \( 8 \)**: This option is incorrect because \( 2^3 = 8 \) is the result of \( 2^3 \) alone, but it does not account for the \( 2^{-1} \) or the squaring of the result.
- **D. \( 32 \)**: This option is incorrect because \( 2^5 = 32 \) is not relevant to our calculations. The exponentiation was done correctly, leading to \( 2^4 \), not \( 2^5 \).
### Revision Summary
- Use the properties of exponents to simplify expressions involving multiplication and powers.
- When multiplying like bases, add the exponents.
- When raising a power to another power, multiply the exponents.
- Always calculate the final result carefully to avoid common pitfalls in exponentiation.
By following these steps, you can confidently simplify similar expressions in the future!