Linear Equations

Linear Equations

Linear equations are fundamental in mathematics and find applications in various fields. They describe relationships that are proportional and can be represented as:

ax + b = 0


  • x is the variable you want to solve for.
  • a and b are constants.

1. Types of Linear Equations:

a. One-Variable Linear Equations: - These equations involve a single variable, typically denoted as x. - Example: 2x + 5 = 11

b. Two-Variable Linear Equations: - These equations involve two variables, often x and y. - Example: 3x + 2y = 8

c. Systems of Linear Equations: - These consist of multiple linear equations with the same variables. 


- 2x + 3y = 10 

- 4x - 5y = 7

2. Solving Linear Equations:

a. Isolating the Variable: - The goal is to isolate the variable (e.g., x) on one side of the equation.

- Use inverse operations (addition, subtraction, multiplication, division) to do this.

b. Balancing Equations: - Perform the same operations on both sides of the equation to keep it balanced.

c. Substitution: - In some cases, you may need to substitute one expression for another to simplify the equation.

3. Common Techniques for Solving Linear Equations:

a. Addition and Subtraction: - Add or subtract constants to both sides of the equation to isolate the variable.

b. Multiplication and Division: - Multiply or divide both sides by constants to isolate the variable.

4. Word Problems:

  • Linear equations are often used to model real-world scenarios. Translate the problem into an equation, solve it, and interpret the results in the context of the problem.

5. Systems of Linear Equations:

  • In systems of linear equations, the goal is to find values of variables that satisfy all the equations simultaneously. Common methods include substitution, elimination, and matrices.

6. Linear Equations in Slope-Intercept Form:

  • The equation y = mx + b is in slope-intercept form, where:
    • y and x are variables.
    • m is the slope of the line.
    • b is the y-intercept (the value of y when x = 0).

7. Linear Equations in Point-Slope Form:

  • The equation y - y₁ = m(x - x₁) represents a line in point-slope form, where:
    • y and x are variables.
    • m is the slope of the line.
    • (x₁, y₁) is a point on the line.