Factorisation of an algebraic expression is the reverse process of expanding.
It involves placing brackets into an expression.
A sum of terms then becomes a product.
Common Factors
If every term of the expression has a common factor, this common factor can be removed and placed outside a set of brackets.
|
Expression
|
Common factor
|
Factors
|
|
6p + 12
|
6
|
6(p + 2)
|
|
6x + 9y − 12z
|
3
|
3(2x + 3y − 4z)
|
|
-2x − 4
|
-2
|
-2(x + 2)
|
|
6xy − 18x
|
6x
|
6x(y − 3)
|
|
5x2 + 10xy |
5x
|
5x(x + 2y)
|
Once an expression has been factorised, it should then be expanded to check it is correct.
Some expressions cannot be factorised.
