Answer
The solution to the inequality \( |2x + 7| - k \leq 5 \) is:
- If \( k \geq -5 \), then \( -\frac{k}{2} - 6 \leq x \leq \frac{k}{2} - 1 \).
- If \( k < -5 \), there are no real solutions.
So, the answer depends on the value of \( k \).
Solution
To solve the inequality:
\[
|2x + 7| - k \leq 5
\]
**Step 1: Isolate the Absolute Value**
First, isolate the absolute value expression by adding \( k \) to both sides:
\[
|2x + 7| \leq k + 5
\]
**Step 2: Understand the Conditions**
For the absolute value inequality \( |A| \leq B \) to have real solutions, the right-hand side \( B \) must be non-negative. Therefore:
\[
k + 5 \geq 0 \quad \Rightarrow \quad k \geq -5
\]
If \( k + 5 < 0 \), the inequality \( |2x + 7| \leq k + 5 \) has no real solutions because an absolute value cannot be negative.
**Step 3: Solve the Absolute Value Inequality**
Assuming \( k \geq -5 \), the inequality \( |2x + 7| \leq k + 5 \) can be rewritten without the absolute value as:
\[
-(k + 5) \leq 2x + 7 \leq k + 5
\]
**Step 4: Solve for \( x \)**
1. **Lower Bound:**
\[
-k - 5 \leq 2x + 7
\]
Subtract 7 from both sides:
\[
-k - 12 \leq 2x
\]
Divide by 2:
\[
-\frac{k}{2} - 6 \leq x
\]
2. **Upper Bound:**
\[
2x + 7 \leq k + 5
\]
Subtract 7 from both sides:
\[
2x \leq k - 2
\]
Divide by 2:
\[
x \leq \frac{k}{2} - 1
\]
**Step 5: Combine the Results**
Putting both bounds together, the solution for \( x \) is:
\[
-\frac{k}{2} - 6 \leq x \leq \frac{k}{2} - 1
\]
**Summary of Solutions:**
- **If \( k \geq -5 \):**
\[
-\frac{k}{2} - 6 \leq x \leq \frac{k}{2} - 1
\]
- **If \( k < -5 \):**
\[
\text{No real solutions}
\]
**Example:**
Suppose \( k = 1 \):
1. Check if \( k \geq -5 \): Yes, since \( 1 \geq -5 \).
2. Compute the bounds:
\[
-\frac{1}{2} - 6 = -6.5 \leq x \leq \frac{1}{2} - 1 = -0.5
\]
3. So, \( x \) lies in the interval \([-6.5, -0.5]\).
Reviewed and approved by the UpStudy tutoring team
Explain
Simplify this solution