Join the IDNLearn.com community and get your questions answered by experts. Our experts are ready to provide in-depth answers and practical solutions to any questions you may have.
Sagot :
To solve the inequality [tex]\(\frac{4}{x-3} + 2 < x + 2\)[/tex] for [tex]\(x < 3\)[/tex], let's follow these steps:
1. Subtract 2 from both sides of the inequality:
[tex]\[ \frac{4}{x-3} + 2 - 2 < x + 2 - 2 \][/tex]
This simplifies to:
[tex]\[ \frac{4}{x-3} < x \][/tex]
2. Isolate the fraction:
We are working with the inequality [tex]\(\frac{4}{x-3} < x\)[/tex]. Note the domain here: [tex]\(x \neq 3\)[/tex] and [tex]\(x < 3\)[/tex].
3. Multiply both sides of the inequality by [tex]\(x-3\)[/tex]:
Since [tex]\(x < 3\)[/tex], [tex]\(x-3\)[/tex] is negative. When multiplying both sides of an inequality by a negative number, the inequality sign reverses.
[tex]\[ 4 < x(x-3) \][/tex]
[tex]\[ 4 < x^2 - 3x \][/tex]
4. Rewrite the inequality in standard form:
[tex]\[ x^2 - 3x - 4 > 0 \][/tex]
5. Factor the quadratic expression:
[tex]\[ x^2 - 3x - 4 = (x - 4)(x + 1) \][/tex]
So, the inequality becomes:
[tex]\[ (x - 4)(x + 1) > 0 \][/tex]
6. Determine the critical points:
The critical points for this inequality are found by setting each factor to zero:
[tex]\[ x - 4 = 0 \implies x = 4 \][/tex]
[tex]\[ x + 1 = 0 \implies x = -1 \][/tex]
7. Test the intervals determined by the critical points:
The critical points divide the number line into three intervals: [tex]\((-\infty, -1)\)[/tex], [tex]\((-1, 4)\)[/tex], and [tex]\((4, \infty)\)[/tex]. Let's test a value from each interval to determine where the inequality holds. However, we are only interested in [tex]\(x < 3\)[/tex].
- For [tex]\(x < -1\)[/tex], choose [tex]\(x = -2\)[/tex]:
[tex]\[ (-2 - 4)(-2 + 1) = (-6)(-1) = 6 \quad (\text{positive}) \][/tex]
- For [tex]\(-1 < x < 4\)[/tex], choose [tex]\(x = 0\)[/tex]:
[tex]\[ (0 - 4)(0 + 1) = (-4)(1) = -4 \quad (\text{negative}) \][/tex]
- For [tex]\(x > 4\)[/tex], choose [tex]\(x = 5\)[/tex]:
[tex]\[ (5 - 4)(5 + 1) = (1)(6) = 6 \quad (\text{positive}) \][/tex]
8. Combine results with the condition [tex]\(x < 3\)[/tex]:
The inequality [tex]\((x - 4)(x + 1) > 0\)[/tex] holds true in the intervals [tex]\((-\infty, -1)\)[/tex] and [tex]\((4, \infty)\)[/tex]. Since we are only interested in values for [tex]\(x < 3\)[/tex], we disregard [tex]\((4, \infty)\)[/tex].
So, the solution that fits both the inequality and the constraint is:
[tex]\[ \boxed{(-\infty, -1)} \][/tex]
Thus, [tex]\(x \)[/tex] must be in the interval [tex]\((-\infty, -1)\)[/tex].
1. Subtract 2 from both sides of the inequality:
[tex]\[ \frac{4}{x-3} + 2 - 2 < x + 2 - 2 \][/tex]
This simplifies to:
[tex]\[ \frac{4}{x-3} < x \][/tex]
2. Isolate the fraction:
We are working with the inequality [tex]\(\frac{4}{x-3} < x\)[/tex]. Note the domain here: [tex]\(x \neq 3\)[/tex] and [tex]\(x < 3\)[/tex].
3. Multiply both sides of the inequality by [tex]\(x-3\)[/tex]:
Since [tex]\(x < 3\)[/tex], [tex]\(x-3\)[/tex] is negative. When multiplying both sides of an inequality by a negative number, the inequality sign reverses.
[tex]\[ 4 < x(x-3) \][/tex]
[tex]\[ 4 < x^2 - 3x \][/tex]
4. Rewrite the inequality in standard form:
[tex]\[ x^2 - 3x - 4 > 0 \][/tex]
5. Factor the quadratic expression:
[tex]\[ x^2 - 3x - 4 = (x - 4)(x + 1) \][/tex]
So, the inequality becomes:
[tex]\[ (x - 4)(x + 1) > 0 \][/tex]
6. Determine the critical points:
The critical points for this inequality are found by setting each factor to zero:
[tex]\[ x - 4 = 0 \implies x = 4 \][/tex]
[tex]\[ x + 1 = 0 \implies x = -1 \][/tex]
7. Test the intervals determined by the critical points:
The critical points divide the number line into three intervals: [tex]\((-\infty, -1)\)[/tex], [tex]\((-1, 4)\)[/tex], and [tex]\((4, \infty)\)[/tex]. Let's test a value from each interval to determine where the inequality holds. However, we are only interested in [tex]\(x < 3\)[/tex].
- For [tex]\(x < -1\)[/tex], choose [tex]\(x = -2\)[/tex]:
[tex]\[ (-2 - 4)(-2 + 1) = (-6)(-1) = 6 \quad (\text{positive}) \][/tex]
- For [tex]\(-1 < x < 4\)[/tex], choose [tex]\(x = 0\)[/tex]:
[tex]\[ (0 - 4)(0 + 1) = (-4)(1) = -4 \quad (\text{negative}) \][/tex]
- For [tex]\(x > 4\)[/tex], choose [tex]\(x = 5\)[/tex]:
[tex]\[ (5 - 4)(5 + 1) = (1)(6) = 6 \quad (\text{positive}) \][/tex]
8. Combine results with the condition [tex]\(x < 3\)[/tex]:
The inequality [tex]\((x - 4)(x + 1) > 0\)[/tex] holds true in the intervals [tex]\((-\infty, -1)\)[/tex] and [tex]\((4, \infty)\)[/tex]. Since we are only interested in values for [tex]\(x < 3\)[/tex], we disregard [tex]\((4, \infty)\)[/tex].
So, the solution that fits both the inequality and the constraint is:
[tex]\[ \boxed{(-\infty, -1)} \][/tex]
Thus, [tex]\(x \)[/tex] must be in the interval [tex]\((-\infty, -1)\)[/tex].
We appreciate every question and answer you provide. Keep engaging and finding the best solutions. This community is the perfect place to learn and grow together. Discover the answers you need at IDNLearn.com. Thank you for visiting, and we hope to see you again for more solutions.