Question
sophia, adola, and Gilly are debating potential values in the solution set of the compound inequality -2 is less than or equal to 2x-2<8. sophie says that -2 is a solution. adola says that 5 is a solution. gilly says 2 is a solution. which person is correct?
Answers
GPT-4o mini
To determine which person's assertion about the solutions to the compound inequality \(-2 \leq 2x - 2 < 8\) is correct, we need to solve the inequality first.
We can break the compound inequality into two parts:
1. \(-2 \leq 2x - 2\)
2. \(2x - 2 < 8\)
**Solving the first inequality:**
\(-2 \leq 2x - 2\)
Add 2 to both sides:
\(-2 + 2 \leq 2x\)
This simplifies to:
\(0 \leq 2x\)
Divide both sides by 2:
\(0 \leq x\)
So, \(x \geq 0\).
**Solving the second inequality:**
\(2x - 2 < 8\)
Add 2 to both sides:
\(2x < 8 + 2\)
This simplifies to:
\(2x < 10\)
Divide both sides by 2:
\(x < 5\).
Now we combine the solutions of the two parts:
The complete solution to the compound inequality is:
\[0 \leq x < 5\]
This means that \(x\) can take values from 0 up to (but not including) 5.
**Evaluating each person's claim:**
1. **Sophie says that -2 is a solution.**
- Since -2 is less than 0, Sophie is incorrect.
2. **Adola says that 5 is a solution.**
- Since 5 is not less than 5, Adola is incorrect.
3. **Gilly says that 2 is a solution.**
- Since 2 is within the range \(0 \leq x < 5\), Gilly is correct.
**Conclusion:**
Only Gilly is correct; the solution set includes the value 2.
We can break the compound inequality into two parts:
1. \(-2 \leq 2x - 2\)
2. \(2x - 2 < 8\)
**Solving the first inequality:**
\(-2 \leq 2x - 2\)
Add 2 to both sides:
\(-2 + 2 \leq 2x\)
This simplifies to:
\(0 \leq 2x\)
Divide both sides by 2:
\(0 \leq x\)
So, \(x \geq 0\).
**Solving the second inequality:**
\(2x - 2 < 8\)
Add 2 to both sides:
\(2x < 8 + 2\)
This simplifies to:
\(2x < 10\)
Divide both sides by 2:
\(x < 5\).
Now we combine the solutions of the two parts:
The complete solution to the compound inequality is:
\[0 \leq x < 5\]
This means that \(x\) can take values from 0 up to (but not including) 5.
**Evaluating each person's claim:**
1. **Sophie says that -2 is a solution.**
- Since -2 is less than 0, Sophie is incorrect.
2. **Adola says that 5 is a solution.**
- Since 5 is not less than 5, Adola is incorrect.
3. **Gilly says that 2 is a solution.**
- Since 2 is within the range \(0 \leq x < 5\), Gilly is correct.
**Conclusion:**
Only Gilly is correct; the solution set includes the value 2.