S3 Maths: Linear Inequalities in One Unknown (Paper 1 (basics))
Paper 1 (basics): ten questions on linear inequalities in one unknown, with answers and notes.
| Item | Detail |
|---|---|
| Questions | 10 |
| Suggested time | 20 |
| Difficulty mix | Foundation 3 · Intermediate 3 · Challenge 3 · Error redo 1 |
| Chapter | Chapter: S3 Maths: Linear Inequalities in One Unknown |
| Level | S3 |
| # | Answer | One-line note |
|---|---|---|
| 1 | x > 3 | Subtract 5 from both sides to obtain x > 3. |
| 2 | x ≤ 6 | Add 4 to both sides to obtain x at most 6. |
| 3 | x < 5 | Divide both sides by 4, which keeps the sign, to obtain x < 5. |
| 4 | x ≥ 4 | Subtract 3 to get 2x at least 8, then divide by 2 to obtain x at least 4. |
| 5 | x < 4 | Add 5 to get 3x < 12, then divide by 3 to obtain x < 4. |
| 6 | x < -4 | Divide both sides by minus 2 and reverse the sign, giving x < -4. |
| 7 | x < 5 | Subtract 2x and add 7 to get 3x < 15, so x < 5. |
| 8 | x ≥ 5 | Expand to 4x – 8 at least 12, then add 8 and divide by 4 to obtain x at least 5. |
| 9 | 6 | With 3x + 4 > 19 we get x > 5, so the smallest integer is 6. |
| 10 | x < -4 | Divide both sides by minus 1 and reverse the sign, so the answer is x < -4. |
Adding or subtracting the same number keeps the inequality sign, while multiplying or dividing by a negative number reverses it. For at least or at most, set up the inequality first and then test the boundary value.Tutor Registration →
Questions and answers are written originally by the TutorZone team and are not taken from any school, publisher or examination authority paper. Every value is checked by computer.
© TutorZone · www.tutorzone.com.hk · For personal study and teaching use only.

