Question 271 of 480
If \( 2^3 \times 2^4 \) is expressed in standard form, what is the result?
- \( 2^7 \)
- \( 8 \times 16 \)
- \( 128 \)
- \( 64 \)
Correct Answer:
A
Explanation
To solve the expression \( 2^3 \times 2^4 \) and express it in standard form, we will follow a systematic approach. Let's break it down step-by-step.
### Step 1: Understanding Exponent Rules
When multiplying numbers with the same base, we can use the rule of exponents that states:
\[
a^m \times a^n = a^{m+n}
\]
In our case, the base \( a \) is \( 2 \), and the exponents are \( 3 \) and \( 4 \).
### Step 2: Applying the Exponent Rule
Using the exponent rule, we can combine the two terms:
\[
2^3 \times 2^4 = 2^{3+4} = 2^7
\]
### Step 3: Expressing in Standard Form
Now that we have simplified the expression to \( 2^7 \), we can also convert this to a numerical value if needed. To do this, we calculate \( 2^7 \):
\[
2^7 = 2 \times 2 \times 2 \times 2 \times 2 \times 2 \times 2
\]
Calculating this step-by-step:
- \( 2 \times 2 = 4 \)
- \( 4 \times 2 = 8 \)
- \( 8 \times 2 = 16 \)
- \( 16 \times 2 = 32 \)
- \( 32 \times 2 = 64 \)
- \( 64 \times 2 = 128 \)
Thus, \( 2^7 = 128 \).
### Step 4: Evaluating the Options
Now, let's evaluate the options provided:
- **Option A: \( 2^7 \)** - This is correct as we derived \( 2^7 \) from the multiplication.
- **Option B: \( 8 \times 16 \)** - This is also equal to \( 128 \) (since \( 8 \times 16 = 128 \)), but it is not in the standard form of \( 2^n \).
- **Option C: \( 128 \)** - This is the numerical value of \( 2^7 \), but it is not in the form of \( 2^n \).
- **Option D: \( 64 \)** - This is incorrect because \( 64 \) is equal to \( 2^6 \), not \( 2^7 \).
### Conclusion
The correct answer is **Option A: \( 2^7 \)** because it directly represents the result of the multiplication in standard form.
### Summary of Key Points
- When multiplying powers with the same base, add the exponents: \( a^m \times a^n = a^{m+n} \).
- \( 2^3 \times 2^4 = 2^{3+4} = 2^7 \).
- The numerical value of \( 2^7 \) is \( 128 \), but the question specifically asks for the standard form.
- Other options either represent the same value in a different form or are incorrect.
This thorough understanding of exponent rules and careful evaluation of options will help you in similar problems in the future!