2.1.1
Algebra Basics
Algebra Rules
Algebra Rules
Here are some common rules of algebra:


Common rules
Common rules
- ab means a × b
- abc means a × b × c
- 5a means 5 × a or a + a + a + a + a


Coefficients
Coefficients
- A number written before an algebraic symbol is called a coefficient.
- In the expression 3x - 4y + z, x has a coefficient of 3, y has a coefficient of -4 and z has a coefficient of 1.


Brackets
Brackets
- We can expand brackets like this.


Common rules
Common rules
- a² means a × a
- a4 means a × a × a × a
- ab²c means a × b × b × c


Common rules
Common rules
- 1⁄2a means 0.5 × a
- 1a means 1 × a but is just written as a
Substituting Values
Substituting Values
For the equation y = 5x² - 3x, what is y when x = 3?
Algebraic Vocabulary
Algebraic Vocabulary
Here are some technical terms for algebra:


Term
Term
- A term is anything which does not include a plus or minus:
- 3x²
- 5x⁄2y


Expression
Expression
- An expression is when terms are combined without an '=' sign:
- 3x
- 6c(5a - b² + 8)


Equation
Equation
- An equation is when terms are combined and a ‘=’ sign is used:
- 5x = 3y
- a + b - c = 0


Inequality
Inequality
- An inequality is when inequality symbols are used (<, ≤, >, ≥):
- 5x < 3
- y ≥ 3x - 2


Identity
Identity
- An identity is when two lines are equivalent for any values of x or y.
- The identity symbol (≡) is used.


Formula
Formula
- A formula is a general rule describing a relationship:
- area of a circle = πr2
- speed = distance⁄time


Factor
Factor
- A factor is a quantity which divides an expression exactly:
- 3 is a factor of 9 and of 12
- 2x is a factor of 4x and of 8x3
1Numbers
1.1Integers
1.3Decimals
1.4Powers & Roots
1.5Set Language & Notation
1.6Percentages
1.7Ratio & Proportion
2Equations, Formulae & Identities
2.1Algebraic Manipulation
2.2Expressions & Formulae
2.3Linear Equations
2.4Quadratic Equations
2.5Proportion
3Sequences, Functions & Graphs
3.1Sequences
3.3Graphs
3.4Common Graphs
4Geometry
4.1Angles, Lines & Triangles
4.2Polygons
4.5Circle Properties
4.6Trigonometry & Pythagoras’ theorem
4.7Mensuration of 2D Shapes
4.83D Shapes & Volume
5Vectors & Transformation Geometry
6Statistics & Probability
6.1Statistical Measures
6.2Graphical Representation of Data
Jump to other topics
1Numbers
1.1Integers
1.3Decimals
1.4Powers & Roots
1.5Set Language & Notation
1.6Percentages
1.7Ratio & Proportion
2Equations, Formulae & Identities
2.1Algebraic Manipulation
2.2Expressions & Formulae
2.3Linear Equations
2.4Quadratic Equations
2.5Proportion
3Sequences, Functions & Graphs
3.1Sequences
3.3Graphs
3.4Common Graphs
4Geometry
4.1Angles, Lines & Triangles
4.2Polygons
4.5Circle Properties
4.6Trigonometry & Pythagoras’ theorem
4.7Mensuration of 2D Shapes
4.83D Shapes & Volume
5Vectors & Transformation Geometry
6Statistics & Probability
6.1Statistical Measures
6.2Graphical Representation of Data
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