Question 377 of 480
What is the value of \( x \) in the equation \( 2^{3x} = 32 \)?
Correct Answer:
B
Explanation
To solve the equation \( 2^{3x} = 32 \), we need to find the value of \( x \). Let's break this down step-by-step.
### Step 1: Rewrite the Right Side of the Equation
First, we can express \( 32 \) as a power of \( 2 \). We know that:
\[
32 = 2^5
\]
So, we can rewrite the equation as:
\[
2^{3x} = 2^5
\]
### Step 2: Set the Exponents Equal
Since the bases are the same (both are base \( 2 \)), we can set the exponents equal to each other:
\[
3x = 5
\]
### Step 3: Solve for \( x \)
Now, we need to isolate \( x \). To do this, we divide both sides of the equation by \( 3 \):
\[
x = \frac{5}{3}
\]
### Step 4: Check the Options
Now, let's compare our answer \( \frac{5}{3} \) with the provided options:
- A. 2
- B. 3
- C. 4
- D. 5
None of these options match \( \frac{5}{3} \). It seems there was a misunderstanding in the recorded correct option. The correct answer is not listed among the options provided.
### Step 5: Verify the Calculation
To ensure our solution is correct, we can substitute \( x = \frac{5}{3} \) back into the original equation:
\[
2^{3(\frac{5}{3})} = 2^5 = 32
\]
This confirms that our solution is indeed correct.
### Explanation of Incorrect Options
- **Option A (2)**: If \( x = 2 \), then \( 3x = 6 \) and \( 2^{3x} = 2^6 = 64 \), which does not equal \( 32 \).
- **Option B (3)**: If \( x = 3 \), then \( 3x = 9 \) and \( 2^{3x} = 2^9 = 512 \), which does not equal \( 32 \).
- **Option C (4)**: If \( x = 4 \), then \( 3x = 12 \) and \( 2^{3x} = 2^{12} = 4096 \), which does not equal \( 32 \).
- **Option D (5)**: If \( x = 5 \), then \( 3x = 15 \) and \( 2^{3x} = 2^{15} = 32768 \), which does not equal \( 32 \).
### Summary
- The equation \( 2^{3x} = 32 \) can be solved by rewriting \( 32 \) as \( 2^5 \).
- Setting the exponents equal gives \( 3x = 5 \), leading to \( x = \frac{5}{3} \).
- None of the provided options (A, B, C, D) are correct as they do not match \( \frac{5}{3} \).
- Always verify your solution by substituting back into the original equation.
### Revision Points
- Understand how to express numbers as powers of their bases.
- When bases are the same, set the exponents equal to solve for the variable.
- Always check your solution by substituting back into the original equation.
- Be cautious of the options provided; they may not always include the correct answer.