Grade 9 Algebra Notes
These notes cover the main Grade 9 algebra topics using simple explanations and examples.
1. Variables and Expressions
• A variable is a letter that represents a number.
• Example: x + 5
• An expression does not have an equals sign.
Example: If x = 3, then x + 5 = 8
2. Combining Like Terms
• Like terms have the same variable.
• Add or subtract the numbers in front of the variable.
Example: 3x + 2x = 5x
3. Distributive Property
• Multiply the number outside the brackets by every term inside.
Example: 4(x + 2) = 4x + 8
4. Solving One-Step Equations
• Use opposite operations to isolate the variable.
Example: x + 7 = 12 → x = 5
5. Solving Two-Step Equations
• Undo addition/subtraction first.
• Then undo multiplication/division.
Example: 2x + 4 = 10 → 2x = 6 → x = 3
6. Graphing Linear Relations
• A linear relation forms a straight line.
• Use x and y values to plot points.
Example: y = 2x + 1
These notes cover the main Grade 9 algebra topics using simple explanations and examples.
1. Variables and Expressions
• A variable is a letter that represents a number.
• Example: x + 5
• An expression does not have an equals sign.
Example: If x = 3, then x + 5 = 8
2. Combining Like Terms
• Like terms have the same variable.
• Add or subtract the numbers in front of the variable.
Example: 3x + 2x = 5x
3. Distributive Property
• Multiply the number outside the brackets by every term inside.
Example: 4(x + 2) = 4x + 8
4. Solving One-Step Equations
• Use opposite operations to isolate the variable.
Example: x + 7 = 12 → x = 5
5. Solving Two-Step Equations
• Undo addition/subtraction first.
• Then undo multiplication/division.
Example: 2x + 4 = 10 → 2x = 6 → x = 3
6. Graphing Linear Relations
• A linear relation forms a straight line.
• Use x and y values to plot points.
Example: y = 2x + 1
