Responder
**6. Solve the inequalities \( 3x + 1 > -10 \) and \( 2 - x > 4 \) for integer \( x \).**
- From \( 3x + 1 > -10 \):
\[
x > -\frac{11}{3} \approx -3.67
\]
- From \( 2 - x > 4 \):
\[
x < -2
\]
- Combining both:
\[
-3.67 < x < -2
\]
- The only integer in this range is:
\[
x = -3
\]
**7. Given \( A = \{x : -3 < x \leq 4\} \) and \( B = \{x : 1 < x < 7\} \):**
**(i) \( A \cap B \):**
\[
A \cap B = \{x : 1 < x \leq 4\}
\]
**(ii) \( A \cup B \):**
\[
A \cup B = \{x : -3 < x < 7\}
\]
Solución
**6. Solve the inequalities \( 3x + 1 > -10 \) and \( 2 - x > 4 \) for integer \( x \).**
1. Start with the first inequality:
\[
3x + 1 > -10
\]
Subtract 1 from both sides:
\[
3x > -11
\]
Divide both sides by 3:
\[
x > -\frac{11}{3}
\]
2. Now, consider the second inequality:
\[
2 - x > 4
\]
Subtract 2 from both sides:
\[
-x > 2
\]
Multiply both sides by \(-1\) (remember to reverse the inequality sign):
\[
x < -2
\]
3. Combine the two inequalities:
\[
-\frac{11}{3} < x < -2
\]
Note that \(-\frac{11}{3} \approx -3.67\). The integers that satisfy the inequality are those greater than \(-3.67\) and less than \(-2\). The only integer in this range is:
\[
x = -3
\]
---
**7. Given \( A = \{x : -3 < x \leq 4\} \) and \( B = \{x : 1 < x < 7\} \), determine:**
**(i) \( A \cap B \)**
The intersection \( A \cap B \) includes those \( x \) that satisfy both:
- \( -3 < x \leq 4 \) (from \( A \))
- \( 1 < x < 7 \) (from \( B \))
The most restrictive conditions are:
- For the lower bound: \( x > 1 \) (since \( 1 > -3 \))
- For the upper bound: \( x \leq 4 \) (since \( 4 < 7 \))
Thus,
\[
A \cap B = \{x : 1 < x \leq 4\}
\]
---
**(ii) \( A \cup B \)**
The union \( A \cup B \) includes any \( x \) that belongs to either \( A \) or \( B \). We have:
- From \( A \): \( -3 < x \leq 4 \)
- From \( B \): \( 1 < x < 7 \)
Together, the union spans all \( x \) from just above \(-3\) up to just below \( 7 \). Notice:
- The lower bound is determined by \( A \): \( x > -3 \)
- The upper bound is determined by \( B \): \( x < 7 \)
Even though \( x = 4 \) is included from \( A \), it does not affect the overall union interval. Therefore,
\[
A \cup B = \{x : -3 < x < 7\}
\]
Respondido por UpStudy AI y revisado por un tutor profesional

Explicar

Simplifique esta solución