Linear Inequalities in Two Variables
Inequality
A statement that one quantity is greater than or less than another, using <, >, ≤ or ≥.
| English | Inequality |
|---|---|
| Bahasa Melayu | Ketaksamaan |
| 中文 | 不等式 |
How it is used
Solving the inequality 3x − 4 < 11 gives 3x < 15, so x < 5; the solution is every value of x below 5, shown as an open circle at 5 on the number line.
Where it shows up in SPM
Introduced in Form 4 (Linear Inequalities in one variable) and used again in Form 5 for two variables. Paper 1 tests solving a one-variable inequality or reading a number line; Paper 2 uses inequalities to set up constraints for a region.
Don't confuse it with
Open the chapter: Linear Inequalities in Two Variables →
Frequently asked questions
Why does the inequality sign flip when I multiply or divide by a negative number?
Multiplying or dividing both sides by a negative reverses the order of the numbers. For −2x < 6, dividing by −2 flips < to >, giving x > −3.
Forgetting to flip is the most common error, so always check with a test value.
How do I write a range like "between 2 and 7" as an inequality?
Combine two conditions into one statement, for example 2 ≤ x ≤ 7 if both ends are included, or 2 < x < 7 if they are not. On a number line, mark 2 and 7 with the matching open or closed circles and shade the segment between them.