Home > Subjects > Mathematics > Level 2 > 2.1 Algebra (AS90284) > Subject content > Expanding in algebra
- Subject: Mathematics
- AS: AS90284
- Level: 2
- Credits: 4
- External
Mathematics 2.1 Manipulate algebraic expressions and solve equations
Expanding in algebra
Expanding is to remove brackets from an algebraic expression.
One bracket
All terms inside the bracket are multiplied by the term outside.
Note that the negative sign belongs to the term directly following it.
e.g. -3(4a – 5) = –3 x 4a + –3 x (–5) = –12a + 15
See online example of multiplying out brackets and expressions that use negative numbers.
Multiplying out two brackets
If there are two brackets, multiply everything in the first bracket by everything in the second bracket. To simplify, add the like terms together.
See online example of multiplying out two brackets.
Brackets and squares
If a bracket is squared, write it as bracket times bracket and expand.
e.g. (2x + 3)2 = (2x + 3)(2x + 3)
= 4x2 + 6x + 6x + 9
= 4x2 + 12x + 9
Algebasics – Section 7: Polynomials (Macromedia Flash® and sound required)
