Edexcel IGCSE Maths 复习笔记 2.16.1 Solving Inequalities - Linear
What is a linear inequality?
- An Inequality tells you that one expression is greater than (“>”) or less than (“<”) another
- “⩾” means “greater than or equal to”
- “⩽” means “less than or equal to”
- A Linear Inequality just has an x (and/or a y) etc in it and no x2 or similar
- For example, 3x + 4 ⩾ 7 would be read “3x + 4 is greater than or equal to 7”
Solving linear inequalities
- Solving linear inequalities is just like Solving Linear Equations (so review these notes first)
- You also need to know how to use Number Lines and deal with “Double” Inequalities
1. Same rules as solving equations: GROF GROBLET FIND ANSWER!
But do NOT multiply (or divide) by negative numbers
2. When drawing NUMBER LINES:
3. For “double” inequalities just do the same thing to all three parts