Question 233 of 480
Evaluate \(\frac{(81^{\frac{3}{4}}-27^{\frac{1}{3}})}{3 \times 2^3}\)
Correct Answer:
B
Explanation
To evaluate the expression \(\frac{(81^{\frac{3}{4}}-27^{\frac{1}{3}})}{3 \times 2^3}\), we will break it down step by step.
### Step 1: Simplify the Numerator
**Calculate \(81^{\frac{3}{4}}\)**:
- First, we recognize that \(81\) can be expressed as \(3^4\) because \(3^4 = 81\).
- Therefore, we can rewrite \(81^{\frac{3}{4}}\) as:
\[
(3^4)^{\frac{3}{4}} = 3^{4 \times \frac{3}{4}} = 3^3 = 27
\]
**Calculate \(27^{\frac{1}{3}}\)**:
- Similarly, \(27\) can be expressed as \(3^3\) because \(3^3 = 27\).
- Thus, we can rewrite \(27^{\frac{1}{3}}\) as:
\[
(3^3)^{\frac{1}{3}} = 3^{3 \times \frac{1}{3}} = 3^1 = 3
\]
### Step 2: Substitute Back into the Expression
Now we substitute these results back into the numerator:
\[
81^{\frac{3}{4}} - 27^{\frac{1}{3}} = 27 - 3 = 24
\]
### Step 3: Simplify the Denominator
**Calculate \(3 \times 2^3\)**:
- First, calculate \(2^3\):
\[
2^3 = 8
\]
- Now, multiply by \(3\):
\[
3 \times 8 = 24
\]
### Step 4: Combine the Results
Now we can substitute the simplified numerator and denominator back into the expression:
\[
\frac{(81^{\frac{3}{4}} - 27^{\frac{1}{3}})}{3 \times 2^3} = \frac{24}{24} = 1
\]
### Conclusion
The final answer is \(1\).
### Explanation of Options
- **Option A: 3** - This is incorrect because the calculations show that the numerator and denominator both simplify to \(24\), leading to a result of \(1\), not \(3\).
- **Option B: 1** - This is correct as we have shown through our calculations that the expression evaluates to \(1\).
- **Option C: \(\frac{1}{3}\)** - This is incorrect because the calculations do not support this value; the result is \(1\).
- **Option D: \(\frac{1}{8}\)** - This is also incorrect as it does not match the evaluated result of \(1\).
### Revision Summary
- \(81^{\frac{3}{4}} = 27\) and \(27^{\frac{1}{3}} = 3\).
- The numerator simplifies to \(24\) and the denominator also simplifies to \(24\).
- The final result of the expression is \(1\).
- The correct answer is option B: \(1\).