Question 285 of 480
Simplify the expression \( 3(x + 4) - 2(2x - 1) \). What is the result?
- \( x + 14 \)
- \( x + 10 \)
- \( x + 5 \)
- \( x + 11 \)
Correct Answer:
B
Explanation
To simplify the expression \( 3(x + 4) - 2(2x - 1) \), we will follow a step-by-step approach.
### Step 1: Distribute the coefficients
First, we need to distribute the coefficients (the numbers outside the parentheses) to the terms inside the parentheses.
1. For the first part, \( 3(x + 4) \):
- Multiply \( 3 \) by \( x \): \( 3 \cdot x = 3x \)
- Multiply \( 3 \) by \( 4 \): \( 3 \cdot 4 = 12 \)
- So, \( 3(x + 4) = 3x + 12 \)
2. For the second part, \( -2(2x - 1) \):
- Multiply \( -2 \) by \( 2x \): \( -2 \cdot 2x = -4x \)
- Multiply \( -2 \) by \( -1 \): \( -2 \cdot -1 = 2 \)
- So, \( -2(2x - 1) = -4x + 2 \)
### Step 2: Combine the results
Now we can combine the results from both distributions:
\[
3(x + 4) - 2(2x - 1) = (3x + 12) + (-4x + 2)
\]
This simplifies to:
\[
3x + 12 - 4x + 2
\]
### Step 3: Combine like terms
Next, we will combine the like terms (the terms that contain \( x \) and the constant terms):
1. Combine the \( x \) terms:
- \( 3x - 4x = -1x \) or simply \( -x \)
2. Combine the constant terms:
- \( 12 + 2 = 14 \)
Putting it all together, we have:
\[
-x + 14
\]
### Step 4: Rewrite the expression
We can rewrite \( -x + 14 \) as:
\[
14 - x
\]
### Final Answer
The simplified expression is \( 14 - x \). However, since the options provided do not include this form, we need to check if we can express it in a way that matches one of the options.
### Evaluating the Options
Now, let's evaluate the options given:
- **A. \( x + 14 \)**: This is incorrect because it suggests that \( x \) is positive and added to 14, which is not the case.
- **B. \( x + 10 \)**: This is incorrect because it does not match our simplified expression.
- **C. \( x + 5 \)**: This is incorrect for the same reason as above.
- **D. \( x + 11 \)**: This is also incorrect.
### Conclusion
None of the options provided match the correct simplified expression \( 14 - x \). Therefore, the correct answer is not listed among the options.
### Revision Summary
- Distribute coefficients to terms inside parentheses.
- Combine like terms carefully.
- Always check if the final expression matches the options provided.
- If the expression does not match any options, re-evaluate the simplification process.
In this case, the correct simplified expression is \( 14 - x \), which does not correspond to any of the provided options.