At Westonci.ca, we connect you with experts who provide detailed answers to your most pressing questions. Start exploring now! Experience the convenience of finding accurate answers to your questions from knowledgeable experts on our platform. Join our platform to connect with experts ready to provide precise answers to your questions in different areas.

Solve the following inequality:
[tex]\[ \frac{x-5}{-x-1} \geq 0 \][/tex]

Write your answer using interval notation.

Sagot :

To solve the inequality

[tex]\[ \frac{x-5}{-x-1} \geq 0, \][/tex]

we will go through several steps to determine the solution set. Here's a detailed step-by-step solution:

### Step 1: Determine the critical points
Critical points occur where the numerator or the denominator is equal to zero, as these are points where the expression can change sign or become undefined.

1. Numerator [tex]\( x - 5 = 0 \)[/tex]:
[tex]\[ x = 5 \][/tex]

2. Denominator [tex]\( -x - 1 = 0 \)[/tex]:
[tex]\[ -x - 1 = 0 \Rightarrow -x = 1 \Rightarrow x = -1 \][/tex]

These critical points divide the number line into intervals that we must test.

### Step 2: Identify the intervals
The critical points [tex]\( x = 5 \)[/tex] and [tex]\( x = -1 \)[/tex] divide the real line into three intervals:
1. [tex]\((-\infty, -1)\)[/tex]
2. [tex]\((-1, 5)\)[/tex]
3. [tex]\((5, \infty)\)[/tex]

### Step 3: Test the intervals

We need to determine the sign of the expression [tex]\(\frac{x-5}{-x-1}\)[/tex] in each interval:

1. For [tex]\( x \in (-\infty, -1)\)[/tex]:
Choose [tex]\( x = -2 \)[/tex]:
[tex]\[ \frac{-2-5}{-(-2)-1} = \frac{-7}{2-1} = \frac{-7}{1} = -7 \][/tex]
The expression is negative.

2. For [tex]\( x \in (-1, 5)\)[/tex]:
Choose [tex]\( x = 0 \)[/tex]:
[tex]\[ \frac{0-5}{-0-1} = \frac{-5}{-1} = 5 \][/tex]
The expression is positive.

3. For [tex]\( x \in (5, \infty)\)[/tex]:
Choose [tex]\( x = 6 \)[/tex]:
[tex]\[ \frac{6-5}{-6-1} = \frac{1}{-7} = -\frac{1}{7} \][/tex]
The expression is negative.

### Step 4: Include the boundaries

We must also consider the boundaries of each interval:

- At [tex]\( x = -1 \)[/tex], the denominator [tex]\(-x - 1\)[/tex] is zero, making the fraction undefined. Thus, [tex]\( x = -1 \)[/tex] cannot be included in the solution set.
- At [tex]\( x = 5 \)[/tex], the numerator [tex]\( x - 5 \)[/tex] is zero, and since zero divided by a non-zero number is zero,
[tex]\[ \frac{0}{-6} = 0, \][/tex]
which satisfies [tex]\( \geq 0 \)[/tex]. Thus, [tex]\( x = 5 \)[/tex] can be included in the solution set.

### Step 5: Combine the results

From our interval testing, the expression is non-negative (i.e., [tex]\(\geq 0\)[/tex]) in the interval [tex]\((-1, 5]\)[/tex].

### Conclusion:

The interval where the inequality is satisfied is:
[tex]\[ (-1, 5] \][/tex]

### Answer in interval notation:
[tex]\[ (-1, 5] \][/tex]