Question 373 of 480
Which of the following expressions is equivalent to \( 3(x + 4) - 2(x - 1) \)?
- \( x + 10 \)
- \( x + 6 \)
- \( 5x + 10 \)
- \( x + 14 \)
Correct Answer:
A
Explanation
To solve the expression \( 3(x + 4) - 2(x - 1) \) and determine which of the provided options is equivalent, we will follow a step-by-step approach.
### Step 1: Distribute the Terms
First, we need to distribute the constants outside the parentheses to the terms inside the parentheses.
1. **Distributing \(3\) to \( (x + 4) \)**:
\[
3(x + 4) = 3x + 12
\]
2. **Distributing \(-2\) to \( (x - 1) \)**:
\[
-2(x - 1) = -2x + 2
\]
### Step 2: Combine the Results
Now, we combine the results from the distributions:
\[
3(x + 4) - 2(x - 1) = (3x + 12) + (-2x + 2)
\]
### Step 3: Simplify the Expression
Next, we combine like terms:
1. Combine the \(x\) terms:
\[
3x - 2x = 1x \quad \text{(or simply } x\text{)}
\]
2. Combine the constant terms:
\[
12 + 2 = 14
\]
Putting it all together, we have:
\[
3(x + 4) - 2(x - 1) = x + 14
\]
### Final Answer
Thus, the expression simplifies to:
\[
x + 14
\]
### Correct Option
The correct option is **D. \( x + 14 \)**.
### Explanation of Other Options
- **Option A: \( x + 10 \)**: This is incorrect because the constant term after simplification is \(14\), not \(10\).
- **Option B: \( x + 6 \)**: This is also incorrect for the same reason; the constant term does not match.
- **Option C: \( 5x + 10 \)**: This option is incorrect because it suggests a different coefficient for \(x\) and a different constant term, which does not match our simplified expression.
### Common Pitfalls
- **Forgetting to distribute correctly**: Always ensure that you distribute the constants to all terms inside the parentheses.
- **Combining like terms incorrectly**: Be careful to only combine terms that are similar (i.e., \(x\) terms with \(x\) terms and constant terms with constant terms).
- **Neglecting the negative sign**: When distributing a negative, ensure that it affects the sign of the terms inside the parentheses.
### Revision Summary
- Distribute constants to terms inside parentheses carefully.
- Combine like terms accurately to simplify expressions.
- Always double-check your final expression against the options provided.
- Be mindful of signs when distributing negative constants.
By following these steps, you can confidently simplify expressions and identify equivalent forms.