Study Notes
Linear equations and inequalities involve expressions where the highest degree of any variable is 1. They are used to represent and solve real-world problems.
- Linear Equation — An equation where the highest degree of any variable is 1. Example: 2x + 3 = 7
- Linear Inequality — A mathematical expression involving symbols like <, >, ≤, and ≥. Example: x > 5
- Solving Inequalities — Finding the range of values that satisfy the inequality. Example: Solve 4 - 2x < 2 to get x > 1
- Graphing Inequalities — Representing inequalities on a number line or Cartesian plane. Example: y > x + 5 can be graphed as a region above the line y = x + 5
Exam Tips
Key Definitions to Remember
- Linear Equation: An equation with the highest degree of 1.
- Linear Inequality: An expression using <, >, ≤, or ≥.
Common Confusions
- Forgetting to reverse the inequality sign when multiplying or dividing by a negative number.
- Mixing up the symbols for 'less than' and 'greater than'.
Typical Exam Questions
- Solve 3x + 2 = 11? Answer: x = 3
- What is the solution to 2(x + 1) > x - 7? Answer: x > -9
- Represent y ≤ x + 5 on a graph? Answer: Shade the region below the line y = x + 5
What Examiners Usually Test
- Ability to solve linear equations and inequalities.
- Understanding of graphing inequalities on number lines and Cartesian planes.
- Application of equations and inequalities to solve word problems.