# Grade 9 Algebra Master Notes
## 1. Variables & Expressions
- A **variable** is a symbol (usually a letter) that represents an unknown value.
- An **algebraic expression** contains numbers, variables, and operations.
- Example: 3x + 5, 7a - 2b + 9
### Simplifying Expressions
- Combine like terms: terms with the same variable and exponent.
- Example: 3x + 7x = 10x
## 2. Order of Operations (BEDMAS)
- Brackets
- Exponents
- Division / Multiplication (left to right)
- Addition / Subtraction (left to right)
Example:
3(2 + 4)^2 − 8 ÷ 2
= 3(6)^2 − 4
= 3(36) − 4
= 108 − 4
= 104
## 3. Solving Linear Equations
### Goal: isolate the variable
Steps:
1. Simplify each side (remove brackets, combine like terms).
2. Move variables to one side.
## 1. Variables & Expressions
- A **variable** is a symbol (usually a letter) that represents an unknown value.
- An **algebraic expression** contains numbers, variables, and operations.
- Example: 3x + 5, 7a - 2b + 9
### Simplifying Expressions
- Combine like terms: terms with the same variable and exponent.
- Example: 3x + 7x = 10x
## 2. Order of Operations (BEDMAS)
- Brackets
- Exponents
- Division / Multiplication (left to right)
- Addition / Subtraction (left to right)
Example:
3(2 + 4)^2 − 8 ÷ 2
= 3(6)^2 − 4
= 3(36) − 4
= 108 − 4
= 104
## 3. Solving Linear Equations
### Goal: isolate the variable
Steps:
1. Simplify each side (remove brackets, combine like terms).
2. Move variables to one side.
