Question 280 of 480
What is the value of \( x \) in the equation \( 2^{x+3} = 32 \)?
Correct Answer:
C
Explanation
To solve the equation \( 2^{x+3} = 32 \), we need to find the value of \( x \). Let's break this down step-by-step.
### Step 1: Understand the Equation
The equation \( 2^{x+3} = 32 \) involves an exponent. The left side has a base of 2 raised to the power of \( x + 3 \), and the right side is the number 32.
### Step 2: Express 32 as a Power of 2
To solve for \( x \), it helps to express both sides of the equation with the same base. We know that:
\[
32 = 2^5
\]
This means we can rewrite the equation as:
\[
2^{x+3} = 2^5
\]
### Step 3: Set the Exponents Equal
Since the bases are the same (both are base 2), we can set the exponents equal to each other:
\[
x + 3 = 5
\]
### Step 4: Solve for \( x \)
Now, we can solve for \( x \) by isolating it:
\[
x + 3 - 3 = 5 - 3
\]
\[
x = 2
\]
### Conclusion
The value of \( x \) is \( 2 \). Therefore, the correct option is **A**.
### Explanation of Other Options
- **Option B (3)**: This is incorrect because if \( x = 3 \), then \( x + 3 = 6 \) and \( 2^6 = 64 \), which does not equal 32.
- **Option C (5)**: This is incorrect because if \( x = 5 \), then \( x + 3 = 8 \) and \( 2^8 = 256 \), which does not equal 32.
- **Option D (7)**: This is incorrect because if \( x = 7 \), then \( x + 3 = 10 \) and \( 2^{10} = 1024 \), which does not equal 32.
### Common Pitfalls
- **Misunderstanding Exponents**: Students often confuse the operations with exponents. Remember that when the bases are the same, you can set the exponents equal.
- **Forgetting to Simplify**: Always simplify your equations step-by-step to avoid mistakes.
### Revision Summary
- Convert numbers to the same base when dealing with exponential equations.
- Set the exponents equal when the bases are the same.
- Solve for the variable by isolating it.
- Check your work by substituting back into the original equation.
By following these steps, you can confidently solve similar exponential equations in the future!