Question 367 of 480
If \( 2^x = 16 \), what is the value of \( x \)?
Correct Answer:
C
Explanation
To solve the equation \( 2^x = 16 \), we need to determine the value of \( x \) that makes this equation true. Let's break this down step-by-step.
### Step 1: Understand the Equation
The equation \( 2^x = 16 \) means that \( 2 \) raised to the power of \( x \) equals \( 16 \). Our goal is to find the exponent \( x \).
### Step 2: Express 16 as a Power of 2
To solve for \( x \), it helps to express \( 16 \) as a power of \( 2 \). We can do this by recognizing that:
\[
16 = 2^4
\]
This means that \( 16 \) can be rewritten in terms of base \( 2 \).
### Step 3: Set the Exponents Equal
Now that we have both sides of the equation in terms of base \( 2 \), we can rewrite the original equation:
\[
2^x = 2^4
\]
Since the bases are the same (both are \( 2 \)), we can set the exponents equal to each other:
\[
x = 4
\]
### Conclusion
Thus, the value of \( x \) is \( 4 \). Therefore, the correct option is:
**C. 4**
### Explanation of Other Options
- **A. 2**: This option suggests that \( 2^2 = 4 \), which is not equal to \( 16 \). Therefore, this option is incorrect.
- **B. 3**: This option suggests that \( 2^3 = 8 \), which is also not equal to \( 16 \). Hence, this option is incorrect.
- **D. 5**: This option suggests that \( 2^5 = 32 \), which is greater than \( 16 \). Therefore, this option is incorrect.
### Common Pitfalls
- **Misunderstanding Exponents**: A common mistake is to confuse the values of exponents. Remember that \( 2^2 = 4 \) and \( 2^3 = 8 \) are much smaller than \( 16 \).
- **Not Recognizing Powers**: Sometimes, students may not recognize that \( 16 \) can be expressed as \( 2^4 \). Familiarity with powers of \( 2 \) can help avoid this mistake.
### Revision Summary
- To solve \( 2^x = 16 \), express \( 16 \) as a power of \( 2 \) (i.e., \( 16 = 2^4 \)).
- Set the exponents equal: \( x = 4 \).
- The correct answer is \( C. 4 \).
- Always check if the bases are the same when dealing with exponential equations.