Looking for reliable answers? Westonci.ca is the ultimate Q&A platform where experts share their knowledge on various topics. Get quick and reliable solutions to your questions from a community of experienced experts on our platform. Get immediate and reliable solutions to your questions from a community of experienced professionals on our platform.

Solve the rational inequality. Write the solution set in interval notation.

[tex]\[ \frac{-4}{1-x} \ \textless \ 9 \][/tex]

What is the solution set?
[tex]\(\square\)[/tex]

(Type your answer in interval notation. Use integers or simplified fractions for any numbers in the expression.)


Sagot :

To solve the rational inequality [tex]\(\frac{-4}{1-x} < 9\)[/tex], we will follow a set of steps to isolate the variable [tex]\(x\)[/tex] and determine the interval solution.

### Step-by-Step Solution:

1. Start with the given inequality:
[tex]\[ \frac{-4}{1-x} < 9 \][/tex]

2. Find the critical point where the denominator is zero:
[tex]\[ 1 - x = 0 \implies x = 1 \][/tex]
This tells us that [tex]\(x = 1\)[/tex] is a point of discontinuity and we should consider this point when solving the inequality.

3. Isolate the variable [tex]\(x\)[/tex]:
First, we need to resolve the inequality by manipulating it algebraically:
[tex]\[ \frac{-4}{1-x} < 9 \][/tex]
Multiply both sides by the expression [tex]\((1-x)\)[/tex], noting that the sign of the inequality will depend on the sign of [tex]\((1-x)\)[/tex]. This step requires consideration of two cases:

Case 1: [tex]\(1 - x > 0\)[/tex] (i.e., [tex]\(x < 1\)[/tex])
[tex]\[ -4 < 9(1 - x) \][/tex]
[tex]\[ -4 < 9 - 9x \][/tex]
Add [tex]\(9x\)[/tex] to both sides:
[tex]\[ 9x - 4 < 9 \][/tex]
Add 4 to both sides:
[tex]\[ 9x < 13 \][/tex]
Divide by 9:
[tex]\[ x < \frac{13}{9} \][/tex]

Case 2: [tex]\(1 - x < 0\)[/tex] (i.e., [tex]\(x > 1\)[/tex])
In this case, the inequality [tex]\(-4 < 9(1-x)\)[/tex] would be reversed if you multiply both sides by a negative number. This complicates the scenario and we should verify the feasible solution.

4. Combining the computed interval:
The first case gives us the interval:
[tex]\[ x < \frac{13}{9} \][/tex]
We also have to consider [tex]\(x \ne 1\)[/tex] due to the undefined nature at this point. This means:

[tex]\[ x \in (-\infty, 1) \cup (1, \frac{13}{9}) \][/tex]

5. Write the solution in interval notation:
The solution set for the given inequality [tex]\(\frac{-4}{1-x} < 9\)[/tex] is as follows in interval notation:
[tex]\[ (-\infty, 1) \cup (1, \frac{13}{9}) \][/tex]

Therefore, the solution set is:
[tex]\[ (-\infty, 1) \cup (1, \frac{13}{9}) \][/tex]

This interval notation represents all values [tex]\(x\)[/tex] where the given inequality holds true, excluding the point where the function is undefined.
Thank you for trusting us with your questions. We're here to help you find accurate answers quickly and efficiently. We hope you found what you were looking for. Feel free to revisit us for more answers and updated information. Thank you for choosing Westonci.ca as your information source. We look forward to your next visit.